A 1.00 molar aqueous solution of trichloroacetic acid (CCl₃COOH) is heated to its boiling point. The solution has the boiling point of 100.18 °C. Determine the van’t Hoff factor for trichloroacetic acid. ( for water = 0.512 K kg mol⁻¹).
Δ = im
(373.18 – 373) K = i × 0.512 K kg mol⁻¹ × 1 m
0.18 K = i × 0.512 K kg mol⁻¹ × 1 m,
i = 0.35
(373.18 – 373) K = i × 0.512 K kg mol⁻¹ × 1 m
0.18 K = i × 0.512 K kg mol⁻¹ × 1 m,
i = 0.35
Explain why on addition of 1 mol of NaCl to 1 litre of water, the boiling point of water increases, while addition of 1 mol of methyl alcohol to one litre of water decreases its boiling point.
The osmotic pressure of a solution is directly proportional to
(a) the molecular concentration of the solute.
(b) the absolute temperature at a given concentration.
(c) the lowering of vapour pressure.
(d) all the above.
The vapour pressure of pure liquids A and B at 400 K are 450 and 700 mm Hg respectively. Find out the composition of liquid mixture if total pressure at this temperature is 600 mm Hg.
State Raoult’s law for a solution containing nonvolatile solute. What type of deviation from Raoult’s law is shown by a solution of chloroform and acetone and why?
Define the following terms :
(i) Mole fraction
(ii) Isotonic solutions
(iii) Van’t Hoff factor
(iv) Ideal solution
(i) Write the colligative property which is used to find the molecular mass of macromolecules.
(ii) In non-ideal solution, what type of deviation shows the formation of minimum boiling azeotropes?
When mercuric iodide is added to the aqueous solution of potassium iodide, the:
(a) Freezing point is raised
(b) Freezing point does not change
(c) Freezing point is lowered
(d) Boiling point does not change
Complete the following chemical equations :
(i) MnO₄⁻(aq) + S₂O₃²⁻(aq) + H₂O(l) →
(ii) Cr₂O₇²⁻(aq) + Fe²⁺(aq) + H⁺(aq) →
(i) State the law which helps to determine the limiting molar conductivity of weak electrolyte.
(ii) Calculate limiting molar conductivity of CaSO₄ (limiting molar conductivity of calcium and sulphate ions are 119.0 and 160.0 Scm² mol⁻¹ respectively)
A 1.00 molar aqueous solution of trichloroacetic acid (CCl₃COOH) is heated to its boiling point. The solution has the boiling point of 100.18 °C. Determine the van’t Hoff factor for trichloroacetic acid. ( for water = 0.512 K kg mol⁻¹).
(i) Following reactions occur at cathode during the electrolysis of aqueous silver chloride solution :
= +0.80 V
= 0.00 V
On the basis of their standard reduction electrode potential (E°) values, which reaction is feasible at the cathode and why ?
(ii) Define limiting molar conductivity. Why conductivity of an electrolyte solution decreases with the decrease in concentration ?
Explain the following observations:
(i) Copper atom has completely filled d orbitals (3d¹⁰) in its ground state, yet it is regarded as a transition element.
(ii) Cr²⁺ is a stronger reducing agent than Fe²⁺ in aqueous solution.
What is meant by elevation in boiling point? Why is it a colligative property?
Define azeotropes. What type of azeotrope is formed by positive deviation from Raoult’s law ?
Give an example.