To observe an elevation of boiling point of 0.05$°$C, the amount of a solute ( mol. wt. = 100) to be added to 100 g of water (K_b= 0.5) is

• 2g

• 0.5g

• 1g

• 0.75g

The measured freezing point depression for a 0.1 m aqueous CH₃COOH solution is 0.19°C. The acid dissociation constant K_a at this concentration will be (Given, K_f the molal cryoscopic constant = 1.86 K kg mol^-1)

• 4.76 × 10^-5

• 4 × 10^-5

• 8 × 10^-5

• 2 × 10^-5

58.4 g of NaCl and 180 g of glucose were separately dissolved in l000 mL of water. Identify the correct statement regarding the elevation of boiling point (b.p) of the resulting solutions.

• NaCl solution will show higher elevation of boiling point

• Glucose solution will show higher elevation of boiling point

• Both the solutions will show equal elevation of boiling point

• The boiling point elevation will be shown by neither of the solutions

Which of the following will show a negative deviation from Raoult's law?

• Acetone-benzene

• Acetone-ethanol

• Benzene-methanol

• Acetone-chloroform

A saturated solution of H₂S in 0.1 M HCl at 25°C contains S^2- ion concentration of 10^-23 mol L^-1. The solubility product of some sulphides are CuS = 10^-44, FeS = 10^-14, MnS = 10^-15 , CdS = 10^-25 . If 0.01 M solution of these salts in 1M HCl are saturated with H₂S, which of these will be precipitated?

• All

• All except MnS

• All except MnS and FeS

• Only CuS

326.

If the elevation in boiling point of a solution of 10 g of solute (mol. wt. = 100) in 100 g of water is $∆{\mathrm{T}}_{\mathrm{b}}$ the ebullioscopic constant of water is

• 10

• 100 T_b

• $∆{\mathrm{T}}_{\mathbf{b}}$

• $\frac{∆{\mathrm{T}}_{\mathrm{b}}}{10}$

Which of these ions is expected to be coloured in aqueous solution?

I. Fe³⁺

II. Ni²⁺

III. Al³⁺

• I and II

• II and III

• I and III

• I, II and III

A 0.1 molal aqueous solution of a weak acid is 30% ionised. If K_f for water is 1.86° C/m, the freezing point of the solution will be

• -0.18$°$C

• -0.54$°$C

• -0.36$°$C

• -0.24$°$C

The freezing point of a solution composed of 10.0 g of KCl in 100 g of water is 4.5°C. Calculate the van't Hoff factor, i for this solution.

• 2.50

• 1.8

• 1.2

• 1.3

During the depression in freezing point experiment, an equilibrium is established between the molecules of

• liquid solvent and solid solvent

• liquid solute and solid solvent

• liquid solute and solid solute

• liquid solvent and solid solute