Thermodynamics ...

Direction (Q. Nos. 1-13) This section contains 13 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONLY ONE option is correct.

Q. If the enthalpy of HCI (g) and Cl^- (aq) are - 92.30 kJ mol^-1 and - 167.44 kJ mol^-1 respectively, then Δ_rH° for the following reaction is

HCI (g) + aq → H⁺ (aq) + Cl^- (aq)

The enthalpy of neutralisation of HS^- (aq) is - 5.1 kJ mol^-1. Thus, second ionisation energy of H₂S is

Given, Δ_fH° of HCI (g) is - 22 . 10 kcal mol^-1 and Δ_SolutionH° (heat of solution) of HCI (g) is - 17.9 kcal mol^-1. Thus, Δ_fH ° of Cl^- (aq) is

Enthalpy of neutralisation of a weak dibasic acid by NaOH is - 24.0 kcal. Thus, enthalpy of ionisation of dibasic acid is

Consider the following reaction,

30 mL of 0.10 MNaOH (aq) + 10 mL of 0.10 M HCI (aq), enthalpy change is .
On further adding 20 mL of 0.10 M HCI (aq), enthalpy change is . Thus, these values are

In the following reactions,

I. 30 mL of 0.1 M Ba(OH)₂(aq) + 30 mL of 0.1 M H₂SO₄ (aq), rise intemperature = ΔT₁
II. 90 mL of 0.1 M Ba(OH)₂(aq) + 90 mL of 0.1 M H₂SO₄ (aq), rise intemperature = ΔT₂. Thus,

Given, CH₃COOH(aq) → CH₃COO^- (aq) + H⁺ (aq), Δ_rH° = 0.005 kcal g^-1

Enthalpy change when 1 mole of Ca(OH)₂, a strong base, is completely neutralised by CH₃COOH (aq) in dilute solution is

For the reactions,

Thus, heat of neutralisation of H₂C₂O₄ (aq) is

Given,

Thus, for the reaction,

Δ_rH° is

Hydration energies of Li⁺ and Cl^- ions are - 499 and - 382 kJ mol^-1 respectively. If lattice energy of LiCI is - 840 kJ mol^-1 then heat of solution of LiCI is 

Enthalpy change on mixing 100 mL of 1 M Ca(OH)₂ with 100 mL of 1 M H₂SO₄ is

Taking each reactant in 1:1 molar ratio, enthalpy changes are and in the following reactions.

 and  are (in kcal)

Direction (Q. Nos. 14) This sectionis based on statement I and Statement II. Select the correct answer from the code given below.
Q. Statement I : Based on the following thermochemical reactions :

Ionisation of HF(aq)is an exothermic reaction.

Statement II : Enthalpy decrease in hydration of H⁺ (aq) and F^- (aq) exceeds the ionisation energy of HF.