Karnataka 2nd PUC Kannada Workbook Answers Pallava Chapter 9 Prabandha Rachane

Karnataka 2nd PUC Chemistry Question Bank Chapter 2 Solutions

Question 21.
Two elements A and B form compounds having formula AB₂ and AB₄. When dissolved in 20 g of benzene (C₆H₆), 1 g of AB₂ lowers the freezing point by 2.3 K whereas 1.0 g of AB₄ lowers it by 1.3 K. Tin molar depression – constant for benzene is 5.1 K kg mol^-1. Calculate atomic masses of A and B.
Answer:


Suppose atomic masses of A and B are ‘a’ and ‘b’ respectively. Then
Molar mass of AB₂ = a + 2b = 110.87 g mol^-1
Molar mass of AB₄ = a + 4b =196.15 g mol^-1
Equation (ii) – Equation (i) gives
2b = 85.28 orb = 42.64
substituting in equation (i) we get
a + 2 × 42.64 = 110.87 or a = 25.59
Thus atomic mass A = 25.59 u
Atomic mass of B = 4.64 u.

Question 22.
At 300 K, 36 g of glucose present in a litre of its solution has an osmotic pressure of 4.98 bar. If the osmotic pressure of the solution is 1.52 bars at the same temperature, what would be its concentration?
Answer:
π = CRT
∴ In the first case,
4.98 = \(\frac{36}{180}\) × R × 300 = 60R
In the second case, 1.52 = C × R × 300
Dividing (ii) by (i), we get C = 0.061 M.

Question 23.
Suggest the most important type of intermolecular attractive interaction in the following pairs.
(i) n-hexane and n-octane
(ii) I₂ and CCl₄
(iii) NaClO₄ and water
(iv) methanol and acetone
(v) acetonitrile (CH₃CN) and acetone (C₃H₆O).
Answer:
(i) Both are non-polar. Hence, inter molecular interactions in them will be London/ dispersion forces (discussed in class XI)
(ii) Both are non-polar. Hence, inter molecular interactions in them will be London/ dispersion forces (discussed in class XI)
(iii) NaClO₄ gives Na+ and ClO₄^– ions in the solution while water is polar molecule. Hence, intermolecular interactions in them will be ion – dipole interactions.
(iv) Both are polar molecules. Hence intermolecular interactions in them will be dipole-dipole interactions.
(v) Both are polar molecules. Hence intermolecular interactions in them will be dipole-dipole interactions.

Question 24.
Based on solute-solvent interactions, arrange the following in order of increasing solubility in n*octane and explain. Cyclohexane, KCl, CH₃OH, CH₃CN.
Answer:
(i) Cyclohexane and n-octane both are non-polar. Hence they mix completely in all proportions.
(ii) KCl is an ionic compound while n-octane is nonpolar. Hence, KCl will not dissolve at all in n-octane.
(iii) CH₃OH and CH₃CN both are polar but CH₃CN is less polar than CH₃OH. As the solvent is non-polar, CH₃CN will dissolve more than CH₃OH is n-octane.
Thus the order of solubility will be KCl< CH₃OH < CH₃CN < Cyclohexane.

Question 25.
Amongst the following compounds, identify which are insoluble, partially soluble and highly soluble in water?
(i) phenol
(ii) toluene
(iii) formic acid
(iv) ethylene glycol
(v) chloroform
(vi) pentanol.
Answer:
(i) Partially soluble (because phenol has
polar-OH group but aromatic phenyl, C₆H₅ – group)
(ii) Insoluble because toluene is non polar while water is polar
(iii) Highly soluble because formic acid can form hydrogen bonds with water.
(iv) Highly soluble because ethylene glycol can form hydrogen bonds with water
(v) Insoluble chloroform is an organic liquid
(vi) Partially soluble because-OH group is polar but the large hydrocarbon part (C₅H₁₁) is nonpolar.

Question 26.
If the density of some lake water is 1.25g mL^-1 and contains 92 g of Na⁺ ions per kg of water, calculate the molality of Na+ ions in the lake.
Answer:
Number of moles in 92 g of Na⁺ ions

As these are present in 1 kg of water, by definition, molality = 4m.

Question 27
If the solubility product of CuS is 6 × 10^-16, calculate the maximum molarity of CuS in aqueous solution.
Answer:
Maximum molarity of CuS in aqueous solution = solubility of CuS in mol L^-1
If S in the solubility of CuS in mol L^-1 , then

Question 28.
Calculate the mass percentage of aspirin (C₉H₈O₄) in acetonitrile (CH₃CN) when 6.5 g of C₉H₈O₄ is dissolved in 450 g of CH₃CN.
Answer:

Question 29.
Nalorphene (C₁₉H₂₁NO₃), similar to morphine, is used to combat withdrawal symptoms in narcotic users. Dose of nalorphene generally given is 1.5 mg. Calculate the mass of 1.5 x 10^-3 m aqueous solution required for the above dose.
Answer:
1.5 × 10^-3 m solution means that 1.5 × 10^-3 mole of nalorphene is dissolved in I kg of water.
Molar mass of C₁₉H₂₁NO₃ = 19 × 12 + 21 + 14 + 48
= 3119 mol^-1
∴ 1.5 × 10^-3 mole of C₁₉H₂₁NO₃;
= 1.5 × 10^-3 × 3119 = 0.467 g = 467 mg
∴ Mass of solution = 1000 g + 0.467 g ‘
=1000.467g
Thus, for 467 mg of nalorphene, solution required =1000.467 g for 1.5 mg of nalorphene, solution required =\(\frac{1000.467}{467} \times 1.5 = 3.219\)

Question 30.
Calculate the amount of benzoic acid (C₆H₅COOH) required for preparing 250 mL of 0.15 M solution in methanol.
Answer:
0.15 M solution means that 0.15 mole of benzoic acid is present in 1 L
i.e. 1000 mL of the solution.
Molar mass of benzoic acid (C₆H₅COOH) = 72 + 5 + 12 + 32 + 1 =122 g mol^-1
∴ 0.15 mole of benzoic acid = 0.15 × 122g= 18.39
Thus, 1000 mL of the solution contain benzoic acid = 18.39
∴ 250 ml of the solution will contain benzoic acid = \(\frac{18.3}{1000}\) × 250= 4.575g

Question 31.
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
Answer:
The depression in freezing points are in the order:
acetic acid < trichloroacetic acid

Fluorine, being most electronegative, has the highest electron withdrawing inductive effect. Consequently, trifluoroacetic acid is the Strongest acid while acetic acid is the weakest acid. Hence, trifluoroacetic acid ionizes to the largest extent while acetic acid ionizes to minimum extent to give ions.in their.solutions . in water. Greater the ions produced, greater is the depression in freezing point. Hence the depression in freezing point is maximum for fluoroacetic acid and minimum for acetic acid.

Question 32.
Calculate the depression in the freezing point of water when 10 g of CH₃CH₂ CHCICOOH is added to 250 g of water. K_a = 1.4 × 10^-3, K_f= 1.86 K kg mol^-1.
Answer:
Molar mass of CH₃CH₂CHCICOOH = 15 + 14 + 13 + 35.5 + 45 = 122.5 g mol^-1

If α is the degree of dissociation of CH₃CH₂CHCICOOH, then CH₃CH₂CHCLCOOH □ CH3CHXHCICOO^– + H +

To calculate vant’s Hoff factor:
CH₃CH₂CHCICOOH □ CH3CH₂HCICOO^– + H⁺

Question 33.
19.5 g of CH₂FCOOH is dissolved in 500 g of water. The depression in the freezing point of water observed is 1.0°C. Calculate the van’t Hoff factor and dissociation constant of fluoroacetic acid. K_f of water is 1.86 K kg mol^-1.
Answer:
Here, w₂ = 19.5 g, w₁, = 500g, K_f = 1.86 K kg mol^-1, (AT_f) obs = 1.0°

M₂ (Calculated) for CH₂ FCOOH = 14+19+45 = 78 g mol^-1
Vant Hoff factor (i) =

calculation of dissociation constant. Suppose degree of dissociation at the given concentration is a.
Then

Taking volume of the solutions as 500ml,

Question 34.
Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water.
Answer:
Here, P° = 17.535 mm, w₂ = 25g,
w₁ = 450g
For solute (glucose, C₆H₁₂O₆, M₂ = 180 g mol^-1
For solvent (H₂O), M₁ = 18g mol^-1
Applying Raoult’s law,

substituting the given values, we get

substituting the given values, we get

Question 35.
Henry’s law constant for the molality of methane in benzene at 298 K is 4.27 x 10s mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.
Answer:
Here, K_H = 4.27 × 10⁵ mm
p = 760 mm
Applying Henry’s law
P = K_H x

i.e, mole fraction of methane in benzene = 1.78 x 10^-3

Question 36.
100 g of liquid A (molar mass 140 g mol^-1) was dissolved in 1000 g of liquid B (molar mass 180 g mol^-1). The vapour pressure of pure liquid B was found to be 500 torr. Calculate the vapour pressure of pure liquid A and its vapour pressure in the solution if the total vapour pressure of the solution is 475 Torr.
Answer:
Number of moles of a liquid

Number of moles of a liquid B (Solvent)

Mole fraction of B in the solution (x_A)

Mole fraction of B in the solution (x_B)
= 1-0.114 = 0.886
Also, given p⁰_B = 500 Torr
Applying Raoult’s law,
P_A = x_AP°_A = 0.114 × P°_A
P_B= x_B p°_B = 0.886 × 500 = 443 Torr
p Total = p_A + p_B
475 = 0.114 P°_A +443 or

Substituting this value in equation (i), we get p_A = 0.114x 280.7 Torr = 32 Torr

Question 37.
Benzene and toluene form ideal solution over the entire range of composition. The vapour pressures of pure benzene and toluene at 300 K are 50. 71mm Hg and 32.06 mm Hg respectively. Calculate the mole fraction of benzene in the vapour phase if 80 g of benzene is mixed with 100 g of toluene.
Answer:
Molar mass of benzene (C₆H₆ = 78 g mol^-1
Molar mass of toluene (C₆H₅CH₃) = 92 g mol^-1
∴ Number of moles in 80 g of benzene

Number of moles in 100 g of toluene

In the solution, mole fraction of benzene

=0.486
mole fraction of toluene = 1-0,486 = 0.514
p° Benzene = 50.71 mm, p° Toluene = 32.06mm
Applying Raoult’s law,
p Benzene= x_Tolucno × p°_Tolucne =0.514 × 32.06 mm = 16.48mm
Mole fraction of benzene in vapour phase

Question 38.
The air is a mixture of a number of gases. The major components are oxygen and, nitrogen with approximate proportion of 20% is to 79% by volume at 298 K. The water is in equilibrium with air at a pressure of 10 atm. At 298 K if the Henry’s law constants for oxygen and nitrogen at 298 K are 3.30 × 10⁷ mm and 6.51 × 10⁷ mm respectively, calculate the composition of these gases in water.
Answer:
Total pressure of air in equilibrium with water = 10 atm
As air contains 20% oxygen and 79% nitrogen by volumes
partial pressure of oxygen :
(P ) = \(\frac{20}{100}\) x 10 atm = 2atm
= 2 x 760 mm = 1520 mm
partial pressure of nitrogen \(P_{N_{2}}\)
= \(\frac{79}{100}\) × 10 atm = 7.9 atm = 7.9 x 760 mm
= 6004 mm

K_H(O₂) = 3.30 x 10⁷mm,K_H (N₂) = 6.51 × 10⁷ mm
Applying Henry’s law

Question 39.
Determine the amount of CaCl (i= 2.47) dissolved in 2.51itre of water such that its osmotic pressure is 0.75 atm at 27° C.
Answer:

Molar mass of CaCl₂= 40 + 2x 35.5 = 111 gmol^-1
Amount dissolved = 0.0308 xlllg = 3.42g

Question 40.
Determine the osmotic pressure of a solution prepared by dissolving 25 mg of K₂SO₄in 2 litre of water at 25° C, assuming that it is completely dissociated.
Answer:
K₂SO₄ dissolved = 0.025g
volume of solution = 2L
T = 250°C = 298 K
Molar mass of K₂SO₄ =
2×39 + 32 + 4 × 16= 174gmol^-1
As, K₂SO₄ dissociates completely as K₂SO₄ → 2K+ SO₄^2-
i.e., ions produced = 3 ∴ i =3

2nd PUC Chemistry Solutions Additional Questions and Answers

Question 1.
How does molarity of a solution change with temperature?
Answer:
Molarity decreases with increase in temperature because volume of solution increases with increase in temperature.

Question 2.
State Raoult’s law.
Ans:
It states that for a solution of volatile liquids its vapour pressure of each component is directly proportional to their mole fraction in the solution.
The relative lowering of vapour pressure is equal to mole fraction of solute in case of non volatile solute.

Question 3.
Why is liquid ammonia bottle first cooled in ice before opening it?
Answer:
At room temperature, the vapour pressure of liquid ammonia is very high. On cooling, vapour pressure decreases. Hence the liquid ammonia will not splash out.

Question 4.
Sodium chloride and calcium chloride are used clear show from the roads. Why?
Answer:
Sodium chloride depresses the freezing point of water to such an extent that it cannot freeze to form ice. Therefore, it melts off easily at the prevailing temperature.

Question 5.
Two liquids A and B boil at 145°C and 190°C
respectively. Which of them has a higher vapour pressure of 80°C? (CBSE 2006)
Answer:
A being more volatile will have higher vapour pressure at 80°C.

Question 6.
Calculate the molality of sulphuric acid solution in which the mole fraction is 0.85.
Answer:

Question 7.
The molar freezing point depression constant for benzene is 4.90 kg mol’1. Selenium exists as polymer. When 3.26 g of selenium is dissolved in 226 g of benzene, the observed freezing point is 0.112°C lower for pure benzene. Decide the molecular formula of selenium (At Wt. of selenium is 78.8 g mol^-1). (CBSE 2002)
Answer:

Question 8.
CCI₄ and water are immiscible whereas ethanol and water are miscible in all proportions. Correlate this behaviour with molecular structure of these compounds. (CBSE 2003,2001)
Answer:
CCI₄ is a non-polar covalent compound.
Water is a polar compound. CCI₄ can neither form H^– bonds with water molecules nor can it break H^– bonds between water molecules. Therefore, it is insoluble in water.

Ethanol is a polar compound and can form H’ bonds with water, which is a polar solvent, therefore it is miscible with water in all proportions.

Question 9.
The molarity of a solution of sulphuric acid is 1.35 M. Calculate its molarity (The density of the acid solution is 1.02 g cm³ )
Answer:
Let the solution be 1 litre or 1000 cm³
∴ Number of moles of H₂SO₄= 1.35
Wt. of solution = 1000 x 1.02 = 1020 g
Wt. of sulphuric acid = 1.35 x 98= 132.3g :
Wt. of water = 1020 – 132.3 = 887.79
Molality of H₂SO₄= ppp x 1000 = 1.52 m

From (i) M, = 110.82, from (ii) M2 = 196.15 AB4 – AB, = B2 196.15- 110.82 = B2 85.33 = B2 B = 42.665
Molar mass of AB2 = Atomic mass of A+ x 2 atomic mass of B 110.82=Atomic mass of A+85.33 Atomic mass of A = 110.82 – 85.33 = 25.49 Atomic mass of A = 25.499 Atomic mass of B = 42.669

Question 10.
Two elements A and B form compounds having molecular formula AB2 and AB4. When dissolved 20 g of C6H6, 1 g of AB2 lowers the freezing point by 2.3 K, whereas 1.0 g of AB„4 lower it by 1.3 K. The molar depression constant for benzene is 5.1 kg mol*1. Calculate the mass of A and B. (CBSE2004)
Answer:
Let the molar mass of AB₂ and AB₄ be M₁and M₂
Then, for AB₂,

From (I) M₁ = 110.82, from (ii) M₁ = 196.15
AB₄– AB₂= B₂
196.15 – 110.82 =B₂
85.33 = B₂
B = 42.665
Molar mass of AB2 = Atomic mass of A+ x 2 atomic mass of B
110.82 = Atomic mass of A+ 85.33
∴ Atomic mass of A = 110.82-85.33 = 25.49
Atomic mass of A = 25 .499
Atomic mass of B = 42.669

Karnataka 2nd PUC Chemistry Question Bank Chapter 14 Biomolecules

2nd PUC Chemistry Biomolecules NCERT Textbook Questions

Question 1.
What are monosaccharides?
Answer:
Monosaccharides are carbohydrates which cannot be hydrolysed to smaller molecules. Their general formula is (CH₂O)_n where n = 3 → 7. These are of two types. Those which contain an aldehyde (-CHO) group are called aldose and those which contain a keto (C = 0) group are called ketose. They are further classified as triose, tetrose, pentose etc. according to the no. of carbon atoms present (3, 4, 5 respectively).

Question 2.
What are reducing sugars?
Answer:
Carbohydrates which reduce Fehling’s solution to red p.pt of Cu₂O or Tollen’s reagent to shining metallic Ag are called reducing sugars. All monosaccharides (both aldoses and ketoses) and disaccharides except sucrose are reducing sugars.

Question 3.
Write two main functions of carbohydrates in plants.
Answer:
1. Structural material for plant cell walls: The polysaccharides cellulose acts as the chief structural material of the plants cell walls.

2. Reserve food material: The polysaccharide starch is the major reserve food material in the plants. It is stored in seeds and acts as the reserve food material for the tiny plant till its capable of making food on its own by photosynthesis.

Question 4.
Classify the following into monosaccharides and disaccharides.
Ribose, 2-deoxyribose, maltose, galactose, fructose and lactose.
Answer:
Monosaccharides: Ribose, 2-deoxyribose, fructose.
Disaccharides: maltose, galactose, lactose.

Question 5.
What do you understand by the term glycosidic linkage?
Answer:
The oxygen linkage through which two monosaccharides are joined together by the loss of a water molecule to form a molecule of disaccharide is called the glycosidic linkage. The glycosidic linkage in maltose molecule is shown below.

Question 6.
What is glycogen? How is it different from starch?
Answer:
Glycogen like starch is a condensation polymer of α – D glucose. Just as glucose is stored in plants in the form of starch it is stored in the form glycogen in human beings. It is present in liver, muscles and brain. When body needs glucose, enzymes breakdown glycogen to provide glucose. It is also present in yeast and fungi.

The main difference between glycogen and starch is that starch is made up of amylose and amylopectin where as glycogen consists of a structure almost same as amylopectin with large number of branching, (amylose has a linear structure and amylopectin has a branched structure with branching after every 25-30 molecules). Glycogen has branching after every 10-15 molecules.

Question 7.
What are the hydrolysis products of
(i) sucrose and (ii) lactose?
Answer:
Both sucrose and lactose are disaccharides sucrose on hydrolysis gives one molecule of α – D glucose and one molecule of β – D – fructose but lactose on hydrolysis gives one molecule of β – D glucose and one molecule of β – D galactose.

Question 8.
What is the basic structural difference between starch and cellulose?
Answer:
Starch is not a single component. It consists of amylose and amylopectin. In contrast, cellulose is a single compound. Amylose is a linear polymer of α – D glucose while cellulose is a linear polymer of β -D glucose. In amylose, C1 – C4 α- glycosidic linkage is present, whereas in cellulose C1 – C4 β- glycosidic linkage is present. Amylopectin has a highly branched structure.

Question 9.
What happens when D-glucose is treated with the following reagents?
(i) HI
(ii) Bromine water
(iii) HNO₃
Answer:

Question 10.
Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.
Answer:
The following reactions of D- glucose cannot be explained by its open chain structure.
1. D – glucose does not undergo certain characteristic reactions of aldehydes. For example glucose does not form NaHSO₃ addition product, aldehyde-ammonia adduct, 2, 4, DNP derivative and does not respond to Schiff’s reagent test.

2. Glucose reacts with NH₂OH to form an oxime but glucose pentaacetate does not. This implies that the aldehyde group is absent in glucose pentaacetate.

3. D (+) – Glucose exists in two stereoisomeric forms ie. α – glucose and β- glucose, α – D (+) – glucose is obtained when a concentrated aqueous or alcoholic solution is crystallised at 303K. It has a melting point of 419K and has a specific rotation of +111° in a freshly prepared aqueous solution. However when glucose is crystallised from water above 371 K β – D (+) glucose is obtained.

4. Both α – D glucose and β – D glucose undergo mutarotation in aqueous solution.

Question 11.
What are essential and non-essential amino acids? Give two examples of each type.
Answer:
α – Amino acids which are needed for health and growth of human beings but are not synthesised by the human body are called essential amino acids. For example, valine, leucine phenylalanine etc. On the other hand α – amino acids which are needed for health and growth of human beings and are synthesised by the human body are called non-essential amino acids. For example glycine, alanine, aspartic acid etc.

Question 12.
Define the following as related to proteins
1. Peptide linkage
2. Primary structure
3. Denaturation.
Answer:
1. Peptide linkage: Proteins are condensation polymers of α – amino acids in which the same or different α – amino acids are connected by peptide bonds. Chemically, a peptide bond is an amide linkage formed between – COOH group of one a – amino acid and – NH₂ group of the other α – amino acid by loss of a molecule of water. Example

2. Primary structure: Proteins may contain one or more polypeptide chains. Each polypeptide chains has a large number of α – amino acids which are linked to one another in a specific sequence. The specific sequence in which the various α – amino acids present in a protein are linked to one another is called its primary structure. Any change in the sequence of α – amino acids creates a different protein.

3. Denaturation: Each protein in the biological system has a unique 3-D structure and has specific biological activity. This is called the native form of the protein. When a protein in its native form is subjected to physical changes like change in temperature, pH etc. hydrogen bonds are broken. Due to the cleavage of hydrogen bonds, unfolding of the protein molecule takes place and it looses its biological activity.

This loss of biological activity is called Denaturation. During denaturation 2° and 3° structures are destroyed but 1° structure remains intact. As a result of denaturation, globules proteins are converted into fibrous proteins. In other words denaturation leads to coagulation. That is why coagulated proteins are called denaturated proteins. Example boiling of egg causes coagulation of egg white.

Question 13.
What are the common types of secondary structure of proteins?
Answer:
The conformations which the polypeptide chains assume as a result of hydrogen bonding is called the secondary structure of proteins. The two types of secondary structures are α -helix and β -pleated sheet structure.

α -helix structure:- In this structure, the -NH group of an amino acid residue forms H-bonds with the > c = o group of the adjacent turn of the right handed screw. (α – helix)

β – pleated.sheet structure:- This structure is called so because it looks like the pleated folds of a drapery. In this structure, all the peptide chains are stretched out to nearly the maximum extension and the then laid side by side. These peptide chains are held together by inter molecular hydrogen bonds.

Question 14.
What type of bonding helps in stabilising the a -helix structure of proteins?
Answer:
The H – bonds formed between the NH group of each amino acid residue and the

group of the adjacent turns of the α – helix help in stabilising the helix.

Question 15.
Differentiate between globul and fibrous proteins.
Answer:

Question 16.
How do you explain the amphoteric- behaviour of amino acids?
Answer:
In aqueous solution, the carboxyl group of an amino acid can loose a proton and the amino group can accept a proton to give a dipolar ion known as zwitter ion

Therefore, in zwitter ion form, the amino acid can both as an acid and a base.

Thus, amino acids show amphoteric behavior.

Question 17.
What are enzymes?
Answer:
Enzyme are proteins that catalyse biological reactions. They are very specific in nature and catalyse only a particular reaction for a particular substrate. Enzymes are usually named after the particular substrate or class of substrate and some times after the particular reaction.
For example: The enzymes used to catalyse the hydrolysis of maltose into glucose is named as malase.

Again, the enzymes used to catalyse the oxidation of one substrate with the simultaneous reduction of another substrate are named as oxidoreductase enzymes. The name of the enzyme ends with 4- ase’.

Question 18.
What is the effect of denaturation on the structure of proteins?
Answer:
As a result of denaturation, globules get unfolded and helixes get uncoiled. Secondary and tertiary structures of protein are destroyed, but the primary structures remain unaltered. It can be said that during denaturation, secondary and tertiary – structured proteins get converted into primary – structured proteins. Also, as the secondary and tertiary structures of a protein are destroyed, the enzyme loses its activity.

Question 19.
How are vitamins classified? Name the vitamin responsible for the coagulation of blood.
Answer:
On the basis of their solubility in water or fat, vitamins are classified into two groups:
1. Fat – soluble vitamins:
Vitamins that are soluble in fat and oils, but not in water, belong to their group.
For example: Vitamins A, D, E and K.

2. Water – soluble vitamins:
Vitamins that are soluble in water belong to their group.
For example: B group vitamins (B₁, B₂, B₆, B₁₂, etc) and vitamin C.
However, biotin or vitamin H is neither soluble in water nor in fat.
Vitamin K is responsible for the coagulation of blood.

Question 20.
Why are vitamin A and vitamin C essential to us? Give their important sources.
Answer:
The deficiency of vitamin A leads to xerophthalmia (hardening of the cornea of the eye) and night blindness. The deficiency of vitamin C leads to scurvy (blending gums). The sources of vitamin A are fish liver oil, carrots, butter and milk. The sources of vitamin C are citrus fruits, amla and green leafy vegetables.

Question 21.
What are nucleic acids? Mention their two important functions.
Answer:
Nucleic acids are biomolecules found in the nuclei of all living cells, as one of the constituents of chromosomes. There are mainly two types of nucleic acids- deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids are also known as polynucleotides as they are long- chain polymers of nucleotides.
Two main functions of nucleic acid are.
1. DNA is responsible for the transmission of inherent characters from one generation to the next. This process of transmission is called heredity.

2. Nucleic acids- (both DNA and RNA) are responsible for protein synthesis in the cell. Even though the proteins are actually synthesised by the. various RNA molecules in a cell, the message for the synthesis of a particular protein is present in DNA.

Question 22.
What is the difference between a nucleoside and a nucleotide?
Answer:
A nucleoside is formed by the attachment of the base to l’ position of sugar.
Nucleoside = Sugar +Base

On the other hand, all the three basic components of nucleic acids (i.e. pentose sugar, phosphoric acid, and base) are present in a nucleotide.
Nucleotide = sugar + Base + Phosphoric acid

Question 23.
The two strands in DNA are not identical but are complementary. Explain.
Answer:
In the helical structure of DNA, the two strands are held together by hydrogen bonds between specific pairs of bases. Cytosine forms hydrogen bond with guanine, while adenine forms hydrogen bond with thymine. As a result, the two strands are complementary to each other.

Question 24.
Write the important structural and functional differences between DNA and RNA.
Answer:
The structure differences between DNA and RNA are as follows:

The functional difference between DNA and RNA are as follows:

Question 25.
What are the different types of RNA found in the cell?
Answer:

• Messenger RNA (m – RNA)
• Ribosomal RNA (r – RNA)
• Transfer RNA (t – RNA)

2nd PUC Biomolecules Additional Questions

Question 1.
What are the expected products of hydrolysis of lactose ?
Answer:
Lactose is a diasacharide on hydrolysis, it gives two molecules of monosaccarides, i.e. one moiecule of each of D – (+) galactose.

Question 2.
Fresh tomatoes are a litter source of vitamin C than those which have been stored for some -time. Explain.
Answer:
On prolonged exposure to air, vitamin C present in tomatoes is destroyed due to aerial oxidation.

Question 3.
Name the vitamin responsible for poor coagulation of blood due to deficiency.
Answer:
Vitamin K.

Question 4.
Ka and Kb values of α – amino acids are very low. Explain. +
Answer:
The K_a and K_b values of α – amino acids, the acidic group is -NH₃ instead of -COOH in carboxylic acids and basic group is -COO instead of NH₂ group in aliphatic amines.

Question 5.
Two samples of DNA, A and B have melting temperature (Tm) 340 and 350k respectively. Can you draw any conclusion from these data regarding their base content?
Answer:
We know that CG base pair has 3 H-bonds and AT base pair has two H-bonds, therefore CG base pair is more stable than AT base pair. Since B has higher melting point than A, B has higher CG content compared to A.

Question 6.
Which polysaccharide is stored in the liver of animals?
Answer:
Glycogen.

Question 7.
What is a prosthetic group?
Answer:
A prosthetic group is a non-protein portion obtained by hydrolysis of conjugated proteins. The main function of prosthetic group is to control the biological functions of proteins.

Question 8.
Name two carbohydrates which can act as biofuels.
Answer:
starch and glycogen.

Question 9.
B – complex is an often prescribed vitamin. What is complex about it and what is its usefulness ?
Answer:
It is a group of vitamins which contains vitamins B₁ B₂, B₆, B₁₂, biotin, pantothenic acid, folic acid and nitotinic acid. Since it is not a single vitamin, but a group of vitamins, it is called vitamin B – complex. It is required to release energy from food and to promote healthy skin and muscles. Its deficiency causes beriberi (vit. B₁ and pernicious anaemia (vit. B₁₂).

Question 10.
Glucose forms an oxime but glucose pentaacetate does not. Explain.
Answer:
Glucose reacts with NH₂OH via open chain form which has the free – CH = O group to form glucose oxime. Glucose pentaacetate, on the other hand, cannot be converted into the open chain form because its anomeric hydroxyl group (C₁ – OH) is acetylated and hence does not form the oxime.

Karnataka 2nd PUC Economics Question Bank Chapter 2 Theory of Consumer Behaviour

2nd PUC Economics Theory of Consumer Behaviour One Mark Questions and Answers

Question 1.
What is Utility?
Answer:
Utility refers to the want-satisfying power of a commodity or a service.

Question 2.
Who introduced the Law of Diminishing Marginal Utility?
Answer:
The German Economist Prof. Gossen introduced the Law of DMU and Prof. Alfred Marshall popularized it.

Question 3.
Define an indifference curve.
Answer:
Indifference curve shows the different combinations of two products from which the consumer gets equal satisfaction.

Question 4.
Define Budget set.
Answer:
It is collection of all bundles of products available to a consumer at the existing market price . at a given level of income.

Question 5.
Define Budget Line.
Answer:
It is locus of different combinations of the two goods which the consumer consumes and whose price exactly equals his income.

Question 6.
What do you mean by monotonic preferences? .
Answer:
When a rational consumer always prefers more of the product which gives him higher level of satisfaction, it is called Monotonic Preferences.

Question 7.
What is MRS?
Answer:
MRS means that as the amount of a commodity with the consumer goes on increasing he is prepared to exchange the other commodity for equal units of the commodity whose amount increasing.

Question 8.
What is an Indifference map?
Answer:
It is a group of Indifference curves for two commodities showing different levels of satisfaction.

Question 9.
Why is MRS always diminishing?
Answer:
If the consumer wants to get additional unit of one product, he has to give up another product to be in same level of satisfaction. Here, when the consumer sacrifices lesser and lesser units of other commodity, the substitution between two goods will be decreasing and hence the MRS diminishes. 4 .

Question 10.
What is Price Ratio?
Answer:
Price ratio refers to the price of the product on the X axis divided by the price of the product on Y axis. PR = Px/Py.

Question 11.
What is Initial Utility? .
Answer:
It refers to.the utility that, is derived by consuming the first unit of a commodity.

2nd PUC Economics Theory of Consumer Behaviour Two Marks Questions and Answers

Question 1.
Differentiate “total utility’ and ‘marginal utility’.
Answer:

Question 2.
What is the difference between Utility and satisfaction?
Answer:

Question 3.
What is ‘Cardinal method’ of utility analysis?
Answer:
When the utility is measured in meters, liters, kilograms, temperature etc., it is called cardinal method of measuring
utility. According to this, utility is measured in terms of numbers like 1,2,3,4,5…… and soon.

Question 4.
Mention any four features of utility.
Answer:

1. Utility is different from satisfaction.
2. Utility is not usefulness always.
3. Utility does not speak about moral principles.
4. Utility is subjective.

Question 5.
What are the properties of a budget line?
Answer:

1. The Budget line slopes downwards from left to right
2. The bundle of goods whose price is equal to consumer’s income lie on the budget line.
3. The bundle of goods whose price is less than consumer’s income lie below budget line.
4. The bundle of goods whose price is more than consumer’s income lie above the budget line.

Question 6.
Write any two limitations of the law of Diminishing Marginal Utility.
Answer:

1. The Law of DMU is not applicable to money.
2. It does not apply to rare collections like ancient coins, stamps, etc.
3. If the consumer is irrational, the law of DMU does not apply.

Question 7.
Can an indifference curve be concave to the origin? Why? .
Answer:
An Indifference Curve cannot be concave to the origin. If an IC is concave, the Marginal Rate of Substitution will be increasing. This is unrealistic. The MRS must always diminish. Such a situation is achieved only when the IC is convex to the origin and not concave.

Question 8.
Find two differences between Budget Line and Budget Set.
Answer:

Question 9.
Why is an IC downward sloping from left to right?
Answer:
IC is negatively sloped. This is because for the consumer to get the same level of satisfaction, the quantity of one
product must decrease when the other is increased.

Question 10.
What does it mean if an IC has a bulge?
Answer:
The bulge in IC shows that the Marginal rate of substitution is not diminishing consistently. Here the consumer is irrational and behaving erratically.

Question 11.
When does a consumer attain equilibrium in IC analysis?
Answer:
The consumer attains equilibrium in IC analysis when the Budget Line is tangent to the Indifference Curve. At the tangential point, the Budget line and the Indifference curve have exactly the same slope. Here, the MRS of Product X and Y are equal to the price ratio of two goods.

Question 12.
Graphically represent the Equilibrium of consumer through IC analysis.
Answer:

2nd PUC Economics Introduction to Micro Economics Five Marks Questions and Answers

Question 1.
What are the differences between cardinal and ordinal approaches to utility analysis?
Answer:

Question 2.
Distinguish between Total Utility and Marginal Utility with the help of an example.
Answer:

Question 3.
Explain the concepts of ‘budget line’ and ‘budget set’ with an example.
Answer:
Budget Set: Budget set is the collection of products that the consumer can buy with his income at the prevailing market prices. It is also known as opportunity set. It includes all the bundles (all possible combinations of two goods) which the consumer can purchase with his given level of income.

Budget Line: Budget line is the graphical representation of all possible combinations Of two goods which cost exactly equal to the income of consumer. It is a locus of different combinations of two goods which the consumer consumes and whose price exactly equals consumer’s income.

The concepts of Budget Set and Budget Line can be explained with this illustration. Suppose a consumer has Rs.40. He spends this on two commodities Mango and Banana. The possible options of spending Rs.40 are given in the form of table as follows. Let us assume that the Price of Mango is Rs.8 each and Banana is Rs.4 each.

In the above diagram, Mangoes are measured along X axis, and Bananas are measured along Y axis. At Point A, the consumer is spending his entire income on Mangoes and at Point F he buys on ly bananas: Between A and F, there are other options like B, C, D, E. By joining these points we get a straight line AF which represents the consumer’s possible purchasing options in spending his entire income of Rs.40 on these two goods at the given prices.

Features or properties of Budget Line:

• The Budget line PQ slopes downwards from left to right indicating that more one product is purchased by reducing the other product.
• The combination of products which are equal to consumer’s income lie on Budget line.
• The combination whose price is less than consumer’s income lie below the Budget line. They show under spending.
• The combination of goods whose price is more, lie above the Budget line. These options are not affordable prices to the consumer.

Slope of Budget Line: The slope of a curve is calculated as a change in the variable on the vertical or Y axis divided by change in the variable on the horizontal or X axis.

Question 4.
Explain any five properties of indifference curves.
Answer:
1. Higher Indifference Curves represent higher levels of satisfaction:
In the diagram, the indifference curve IC₂ lies above and to the right of the Indifference curve IC₁. Since IC₂ is the higher indifference Curve, it shows higher satisfaction. Like wise IC₃ lies above IC₂.

2. ICs must slope from left downward to the right:

Indifference curves must slope down from left to the right, ie., they must have a negative slope. Our assumption that the consumer would like to have more of both goods helps in proving this. As we move from left to the right on an IC, it means more of the commodity represented on the X axis. With every increase in the amount of one commodity, the consumer becomes better off.

3. Indifference curves do not intersect:

The indifference curves can never meet or intersect so that only one indifference curve can pass through any one point in the indifference map. In Other words, one combination of goods can lie only on one IC. In the diagram given below, two indifference curves IC, and IC₂ intersect each other at E. Since points C and E lie on the same indifference curve IC„ the consumer is indifferent between them. But both are giving him different levels of satisfaction which is not possible if he is in same difference curve.

If the two IC_s intersect, the same IC show different level of satisfaction.In the above
diagram ‘A’ and ‘B’ are representing two levels of satisfaction which is absurd, similarly incase of IC₂ also.

4. Indifference Curves are convex to the origin:

The MRS between two goods diminishes as we move from left down to the right along the IC as shown below. Points P and Q lie on indifference curve IC. As we move from P to Q, there is an increase of commodity A but a corresponding lessening of commodity B. That means MRS goes on diminishing along the IC. So IC should be convex to the origin.

5. The IC cannot be a vertical or a horizontal line:

If IC is vertical or horizontal, it means that the consumer consumes by changing only one commodity without altering the consumption of other commodity. This cannot be true as the consumer is changing consumption of both the commodities to get maximum satisfaction.

If it is vertical, product x remains the same and if it is horizontal, product y remains the same. But this cannot lead to substitution.

2nd PUC Economics Theory of Consumer Behaviour Ten Marks Questions and Answers

Question 1.
Explain the law of diminishing marginal utility with a schedule and diagram. ‘
Answer:
One of the most important propositions of the cardinal utility approach to demand was the Law of Diminishing Marginal Utility. German Economist Gossen was the first to explain it. Therefore, it is called Gossen’s First Law.

Definition:
According to Alfred Marshall, “The additional benefit which a person derives from a given increase of a stock of a thing diminishes, other things being equal, with every increase in the stock that he already has”.
This law simply tells us that, we obtain less and less utility from the successive units of a * commodity as we consume more and more of it.

Assumptions of the Law of DMU :

• Uniform quality and size of the commodity: The Successive units of the commodity should not differ in any way either in quality or size.
• Suitable quantity of consumption: The commodity units should not be very small; e.g. Milk should be in glasses and not in spoons.
• Consumption within the same time: Consumption must be continuous. There should not be too much time difference between the consumption of successive units.
• No change in the mental condition of the consumer during consumption: The consumer should not feel any change in his mental condition due to the consumption of the commodity.
• No change in fashion or taste: The law applies only When consumer’s taste for it remains the same.
• No change in the price of the commodity or its substitutes: The law is based on the assumption that the commodity’s price does not change for successive units. The price of the substitutes is also to be kept at the same level.
• Utility can be measured in cardinal numbers i.e., 1,2, 3, 4,
• Consumer must be rational, i.e., every consumer wants to maximize his satisfaction.

Explanation of Law of Diminishing Marginal Utility:
The basis of this law is that every want of us needs to be satisfied only upto a limit. After this limit is reached the intensity of our want becomes zero. It is called complete satisfaction of the want. Therefore, as we consume more and more units of a commodity to satisfy our need, the intensity of our want for it becomes less and less. Therefore, the utility obtained from the consumption of every additional unit of the commodity is less than that of the units consumed earlier. This can be explained with the help of the following table. TU-Total Utility ,MU-Marginal Utility.

Suppose a man wants to consume apples and is hungry. In this condition, if he gets one apple, he has maximum utility for it. Let us say that the measurement of this utility is equal to 30 units. Having eaten the first he will not remain that hungry as before. Therefore, if he consumes the second apple he will have a lesser amount of utility from it even if it was exactly like the first one. The utility he gets from the second apple equals 20 units, the third, fourth, fifth and sixth apples give him utilities equal to 15,10, 5 and 2 units respectively.’ Now, if he is given the seventh apple he has no use for it. That means the utility of the seventh apple to the consumer is zero. It is just possible that if he is given the eighth apple for consumption,’ it may be detrimental. Here the utility Will be negative ie., -2. Therefore, we are clear that the additional utility of the successive apples to the consumer goes on diminishing as he consumes more and more of it.

The Law of Diminishing Marginal Utility can be explained with the help of the following diagram.

In the diagram the horizontal axis shows the units of apples and the vertical axis measures the MU and TU obtained from the apple units. The total utility Curve will be increasing in the beginning and later falls. The Marginal Utility curve is falling from left down to the right clearly tells us that the satisfaction derived from the successive consumption of apples is falling.

The Marginal Utility of the first apple is known as initial utility. It is 30 utils. The Marginal utility of the seventh apple is Zero. Therefore, this point is called the satiety point. The Marginal Utility of the eighth apple is -2. So, it is called Negative utility and lies below the X axis.

Question 2.
Explain the indifference curve and indifference map with the help of schedule and diagrams.
Answer:
An Indifference Curve is the locus of all those points representing various combinations of two goods giving the same satisfaction to the Consumer.

According A.L.Meyers, “An Indifference curve is a schedule of various combinations of goods which will be equally satisfactory to the consumer concerned.”

Indifference Schedule:
An Indifference Schedule is a table representing the various combinations of goods which give equal satisfaction to the consumer. The following table shows the indifference schedule of combinations of Biscuits and cups of Tea for a consumer

In the above table it is assumed that consumer is purchasing combination of cups of tea and biscuits. He is indifferent between the five combinations given above. Combination A shows that the consumer has one cup of tea and 50 biscuits, while combination B shows that the consumer gets two cups of tea and 8 biscuits. The consumer is indifferent between these combinations since they give him the same level of satisfaction. Similar is the case with the other combinations i.e., C, D and E.
Indifference curve : It shows the different commodities in which consumers get equal satisfaction.

In the above diagram, IC is an Indifference curve. The different points on it show the various combinations of Tea and Biscuits. The consumer likes all of them equally. He is indifferent about his choice. By joining these points we obtain the IC. Although in the successive combinations the amount of biscuits goes on diminishing as we move from the left side of the IC to the right, the increase in the quantity of cups of tea is sufficient to compensate him for the loss of biscuits so that the consumer is indifferent about them.

Indifference curve shows the different combinations of two commodities in which consumers get equal satisfaction, indifference Map: It refers to a set of indifference curves for two commodities showing different levels of satisfaction. The higher indifference curves show higher level of satisfaction and lower IC. represents lower satisfaction. A rational consumer always chooses more of that product that offers him a higher satisfaction and represent in higher IC. It is also called ‘Monotonic preferences’.

In the above diagram IC₄ gives higher level of satisfaction and the IC₁ gives lowest level of satisfaction.

Question 3.
Explain the consumer’s equilibrium through indifference curve analysis.
Answer:
A consumer tries to achieve maximum satisfaction with his limited Budget. Now to know his equilibrium i.e., maximum satisfaction, we have to combine ICs with the Budget line. Assumptions of Consumer Equilibrium:

•  Income of consumer remains constant.
• Consumer behaves rationally and he tries to get maximum satisfaction from his limited income.
• Prices of commodities remain constant.
• Consumer is aware of the indifference map.
• All goods are homogeneous and divisible.
• The condition of transitivity is satisfied i.e., if combination A >B, and B>C, then A>C.
• The condition of non-satiety holds good. The consumer either prefers one of the products or both the products equally.

The consumer is said to be in equilibrium when his budget line is tangent to the Indifference curve. This can be explained with the help of the following diagram.

In the above diagram, PQ is budget line. IC₁, IC₂, and IC₃ are Indifference curves. At point ‘E’, the budget line is tangent to Indifference curve IC₂,.

The consumer has attained his optimal choice at point E where he buys OM quantity of product x and ON quantity of product y within his budget to get maximum satisfaction. If he selects point below E, he is wasting his money income and the combinations above this are point are not possible as his income is not sufficient. At Point E, the Budget line and IC₂ tangent. This can be expressed as follows:

That means the willingness to substitute is equivalent to the ability to pay. So, a consumer is said to be in equilibrium if his budget line is tangent to IC or when the MRS is equal to the price ratio of the-two goods, PQ is the budget line.

The points other than E are not equilibrium points. For instance, Points A and D are not equilibrium points of consumer as they lie above the budget line. The points B and C lie in IC₁, which gives him lower satisfaction for the same budget. Hence, the consumer attains equilibrium only at point E.

Question 4.
Explain the properties of indifference curve.
Answer:
1. Higher Indifference Curves represent higher levels of satisfaction:
In the diagram, the indifference curve IC₂ lies above and to the right of the Indifference curve IC₁. Since IC₂ is the higher indifference Curve, it shows higher satisfaction. Like wise IC₃ lies above IC₂.

2. ICs must slope from left downward to the right:
Indifference curves must slope down from left to the right, ie., they must have a negative slope. Our assumption that the consumer would like to have more of both goods helps in proving this. As we move from left to the right on an IC, it means more of the commodity represented on the X axis. With every increase in the amount of one commodity, the . consumer becomes better off.

3. Indifference curves do not intersect: The indifference curves can never meet or intersect so that only one indifference curve can pass through any one point in the indifference map. In other words, one combination of goods can lie only on one IC. In the diagram given below, two indifference curves IC₁, and IC₂, intersect each other at E. Since points C and E lie on the same indifference curve IC₂, the consumer is indifferent between them. But both are giving him different levels of satisfaction which is not possible if he is in same indifference curve.

If the two ICs intersect, the same IC show different level of satisfaction. In the above diagram ‘A’ and ‘B’ are representing two levels of satisfaction which is absurd, similarly incase of IC₂, also.

4. Indifference Curves are convex to the origin: The MRS between two goods diminishes as we move from left down to the right along the IC as shown below. Points P and Q lie on indifference curve IC. As we move from P to Q, there is an increase of commodity A but a corresponding lessening of commodity B. That means MRS goes on diminishing along the IC. So IC should be convex to the origin.

5. The IC cannot be a vertical or a horizontal line: If IC is vertical or horizontal, it means that the consumer consumes by changing only one commodity without altering the consumption of other commodity. This cannot be true as the consumer is changing consumption of both the commodities to get maximum satisfaction.

If it is vertical, product x remains the same and if it is horizontal, product y remains the same. But this cannot lead to substitution.

6. IC cannot be a downward sloping straight line: A straight line IC shows perfect substitutes on the X and Y axis; therefore, the MRS remains the same in spite of the fact that the stock of one good continues to increase and that of the other diminishes.

7. An IC cannot be concave to the origin: An IC cannot be concave. If it is concave, it shows increasing marginal rate of substitution which is not possible in case of IC analysis.

8. IC cannot be positively sloped: If IC slopes upwards -positively, it means that the consumer prefers more units of both the commodities, which is not possible.

9. If the IC, are parallel, the marginal rate of substitution diminishes at the same rate. Bay, this is not true.

10. The ICs do not touch the horizontal or the Vertical axes: Indifference curves have the basic assumption that the consumer purchases combinations of different commodities. Therefore, he is not supposed to purchase only one commodity because in that case the IC will touch one axis. Purchasing only one commodity means monomania i.e., consumer’s lack of interest in the other commodity.

11. An IC cannot have a bulge: The bulge in IC shows that the Marginal rate of substitution is
not diminishing consistently. Here the consumer is irrational and behaving erratically.

Karnataka 2nd PUC Kannada Workbook Answers Pallava Chapter 8 Kriya Padagalu, Dhatu, Kala Suchaka Galu, Nishedharthaka Rupa