sol ch 1

Question 1

Henry’s Law

Answer 1

the solubility of a gas in a liquid, at a constant temperature, is directly proportional to the partial pressure of the gas

Question 2

Raoult’s Law

Answer 2

According to Raoults Law, the vapour pressure of a solution containing a non-volatile solute is directly proportional to the mole fraction of the solvent ( XA). The proportionality constant being the vapour pressure of the pure solvent, i.e., P× XA or P = P° XA.

Question 3

What is molarity?

Answer 3

Molarity, or molar concentration, is the concentration of a solution measured as the number of moles of solute per litre of solution.

Question 4

Characteristics of an ideal solution:

Answer 4

a) ∆sol V = 0, i.e., there is no change in volume when an ideal solution is formed.
(b) ∆sol H= 0; i.e., heat is neither evolved nor absorbed during the formation of an ideal solution.

Question 5

ideal solution examples

Answer 5

benzene toluene
bromoethane chloroethane

Question 6

Colligative properties?

Answer 6

Colligative properties of solutions are those properties which depend only upon the number of solute particles in the solution and not on their nature. Such properties are
(a) Relative lowering in vapour pressure,
(b) Elevation of boiling point,
(c) Depression of freezing point and
(d) Osmotic pressure.

Question 7

ideal soln interaction p

Answer 7

A-B weal A-A B-B strong

Question 8

ideal soln interaction n

Answer 8

A-B strong A-A B-B weak

Question 9

positive eg

Answer 9

acetol ethanol
acetol CS2
water methanol

Question 10

negative eg

Answer 10

acetone aniline
acetone chloroform
HNO3 H2O

Question 11

azeotrope

Answer 11

a mixture of compounds with the same composition in the vapour as in the liquid