In an ice calorimeter, a chemical reaction is allowed to occur in thermal contact with an ice-water mixture at 0°C. Any heat liberated by the reaction is used to melt some ice. When solutions containi

Question

In an ice calorimeter, a chemical reaction is allowed to occur in thermal contact with an ice-water mixture at 0°C. Any heat liberated by the reaction is used to melt some ice. When solutions containing 2.0 millimole each of BaCl₂ and Na₂SO₄ were mixed in such a calorimeter, both solutions having been pre-cooled to 0°C, 0.50 g of ice melted. Assuming complete reaction, what is ΔH for the reaction: Ba²⁺(aq) + SO₄^2-(aq) → BaSO₄(s)? Latent heat of fusion of ice at 0°C is 80 cal/g.

Options:

Answer:

C

Solution:

Heat released = 0.50 g × 80 cal/g = 40 cal for 2.0 millimole. Per mole: 40/0.0020 = 20000 cal = 20 kcal. Heat is liberated: ΔH = -20 kcal/mol. This is option (c).

TestHub · Accepted Answer

Heat released = 0.50 g × 80 cal/g = 40 cal for 2.0 millimole. Per mole: 40/0.0020 = 20000 cal = 20 kcal. Heat is liberated: ΔH = -20 kcal/mol. This is option (c).

Chemistry - Thermochemistry Question with Solution | TestHub

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