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Solutions · Question 19

JEE Main 2026 (Online) 22nd January Morning ShiftMCQMedium📈 Topic in 10% papers+4−1
1

Consider a solution of CO2(g) dissolved in water in a closed container. Which one of the following plots correctly represents variation of log (partial pressure of CO2 in vapour phase above water) [y-axis] with log (mole fraction of CO2 in water) [x-axis] at 25 ?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]

Answer

(3) [figure]

Solution

Henry's law: pCO2 = KH xCO2

pCO2 = xCO2 + KH

Comparing with y = mx + c: slope = 1 (a rising straight line) and intercept = KH.

For CO2 in water at 298 K, KH = 1.67 108 Pa (NCERT) KH is positive.

The plot is a straight line of positive slope with a positive intercept on the y-axis.

Answer: (3)

JEE Main 2026 (Online) 22nd January Morning Shift

Keep practising — Solutions

2

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below

  1. Both Statement I and Statement II are true
  2. Statement I is true but Statement II is false
  3. Statement I is false but Statement II is true
  4. Both Statement I and Statement II are false
JEE Main 2026 (Online) 22nd January Morning Shift
3

Elements P and Q form two types of non-volatile, non-ionizable compounds PQ and PQ2. When 1 g of PQ is dissolved in 50 g of solvent 'A', Tb was 1.176 K while when 1 g of PQ2 is dissolved in 50 g of solvent 'A', Tb was 0.689 K. (Kb of 'A' = 5 K kg mol-1). The molar masses of elements P and Q (in g mol-1) respectively, are :

  1. 25, 60
  2. 60, 25
  3. 65, 145
  4. 70, 110
JEE Main 2026 (Online) 21st January Morning Shift
4

The osmotic pressure of a living cell is 12 atm at 300 K. The strength of sodium chloride solution that is isotonic with the living cell at this temperature is g L-1. (Nearest integer) Given : R = 0.08 L atm K-1 mol-1 Assume complete dissociation of NaCl (Given: Molar mass of Na and Cl are 23 and 35.5 g mol-1 respectively.)

JEE Main 2026 (Online) 21st January Evening Shift
5

A substance 'X' (1.5 g) dissolved in 150 g of a solvent 'Y' (molar mass = 300 g mol-1) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent 'Y' is 10-2. (nearest integer) [Given: Kb of the solvent = 5.0 K kg mol-1] Assume the solution to be dilute and no association or dissociation of X takes place in solution.

JEE Main 2026 (Online) 21st January Evening Shift
6

HA(aq) H+(aq) + A-(aq) The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 C. The dissociation constant for the acid is Given: Kf(H2O) = 1.8 K kg mol-1, molality ≡ molarity

  1. 1.90 10-3
  2. 1.38 10-3
  3. 1.1 10-2
  4. 1.89 10-1
JEE Main 2025 (Online) 8th April Evening Shift
7

Which of the following binary mixtures does not show the behaviour of minimum boiling azeotropes?

  1. CH3OH + CHCl3
  2. C6H5OH + C6H5NH2
  3. H2O + CH3COC2H5
  4. CS2 + CH3COCH3
JEE Main 2025 (Online) 8th April Evening Shift
8

The percentage dissociation of a salt (MX3) solution at given temperature (van't Hoff factor i = 2) is % (Nearest integer)

JEE Main 2025 (Online) 7th April Morning Shift
9

Liquid A and B form an ideal solution. The vapour pressures of pure liquids A and B are 350 and 750 mm Hg respectively at the same temperature. If xA and xB are the mole fraction of A and B in solution while yA and yB are the mole fraction of A and B in vapour phase, then,

  1. (xA - yA) < (xB - yB)
  2. xAxB = yAyB
  3. xAxB < yAyB
  4. xAxB > yAyB
JEE Main 2025 (Online) 7th April Evening Shift
10

Match List - I with List - II. Choose the correct answer from the options given below :

  1. A-III, B-I, C-IV, D-II
  2. A-III, B-IV, C-I, D-II
  3. A-II, B-I, C-IV, D-III
  4. A-II, B-IV, C-I, D-III
JEE Main 2025 (Online) 7th April Evening Shift
11

XY is the membrane/partition between two chambers 1 and 2 containing sugar solutions of concentration c1 and c2 (c1 > c2) mol L-1. For the reverse osmosis to take place identify the correct condition. (Here p1 and p2 are pressures applied on chamber 1 and 2.) [figure] Choose the correct answer from the options given below:

  1. A and C Only
  2. A and D Only
  3. B and D Only
  4. C Only
JEE Main 2025 (Online) 4th April Morning Shift

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