Neco 2021 Chemistry Question 28

Practice objective / multiple choice question 28 from the 2021 Neco Chemistry examination.

Neco 2021 Chemistry Objective / Multiple Choice Medium Difficulty
Question 28 NECO • 2021 • CHEMISTRY • objective

The solubility of KNO₃ in water is 32\,g per 100\,g water at 20\,°C and 66\,g per 100\,g water at 40\,°C. Assuming the enthalpy of dissolution is constant over this temperature range, (a) calculate the enthalpy change (ΔH_{sol}) in kJ·mol⁻¹ using the van\'t Hoff equation, and (b) estimate the solubility (in g per 100\,g water) at 60\,°C.

Answer Options

A. ΔH_{sol} ≈ 22.0\,kJ·mol⁻¹; solubility at 60\,°C ≈ 110\,g per 100\,g water
Correct Answer B. ΔH_{sol} ≈ 27.5\,kJ·mol⁻¹; solubility at 60\,°C ≈ 124\,g per 100\,g water
C. ΔH_{sol} ≈ 15.2\,kJ·mol⁻¹; solubility at 60\,°C ≈ 95\,g per 100\,g water
D. ΔH_{sol} ≈ 34.8\,kJ·mol⁻¹; solubility at 60\,°C ≈ 140\,g per 100\,g water
Correct Answer
B
Correct Option:
ΔH_{sol} ≈ 27.5\,kJ·mol⁻¹; solubility at 60\,°C ≈ 124\,g per 100\,g water

About This Question

This is Neco 2021 Chemistry Question 28. It is one of the objective questions from the 2021 Neco Chemistry examination.

Difficulty level: Medium .

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