Define vapour pressure of a liquid. What happens to the vapour pressure of a liquid when (a) a volatile solute dissolves in it and (b) a non-volatile solute dissolves in it?

Solution

Answer:

Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system.

(a) When a volatile solute is dissolved in a liquid total vapour pressure is given by the sum of total vapour pressure of both the solvent and solute ie.,
P = P_A + P_B.

(b) When a non-volatile solute is dissolved in a liquid, the vapour pressure of liquid decreases and this lowering of vapour pressure is proportional to the mole fraction of solute added to it.

$\frac{P_{A}^{0} - P_{A}}{P_{A}^{0}} = X_{B}$

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Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

Amongst the following compunds identify which are insoluble, partially soluble and highly soluble in water?
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Solutions

Define vapour pressure of a liquid. What happens to the vapour pressure of a liquid when (a) a volatile solute dissolves in it and (b) a non-volatile solute dissolves in it?

Some More Questions From Solutions Chapter

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

Amongst the following compunds 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.

Two liquids A and B boils at 145⁰C and 190⁰C respectively. Which of them has a higher vapour pressure at 80⁰C ?

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Solutions

Define vapour pressure of a liquid. What happens to the vapour pressure of a liquid when (a) a volatile solute dissolves in it and (b) a non-volatile solute dissolves in it?

Some More Questions From Solutions Chapter

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 370C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

Amongst the following compunds 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.

Two liquids A and B boils at 1450C and 1900C respectively. Which of them has a higher vapour pressure at 800C ?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Amongst the following compunds 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.

Two liquids A and B boils at 145⁰C and 190⁰C respectively. Which of them has a higher vapour pressure at 80⁰C ?