The reversible reaction: Na 2 SO 4 · 10H 2 O → Na 2 SO 4 + 10H 2 O; ΔH = +16.1 kcal goes completely to the right at temperature above 32.4°C and remains completely on the left below this temperature.

Question

The reversible reaction: Na 2 SO 4 · 10H 2 O → Na 2 SO 4 + 10H 2 O; ΔH = +16.1 kcal goes completely to the right at temperature above 32.4°C and remains completely on the left below this temperature. This system has been used in some solar houses for heating at night with the energy absorbed from the sun's radiation during the day. How many litres of fuel gas could be saved per night by the reversal of the dehydration of a fixed charge of 100 kg Na 2 SO 4 ·10H 2 O? Assume that the fuel value of the gas is 10,000 kcal/m 3 .

TestHub · Accepted Answer

Moles of Na ₂ SO ₄ ·10H ₂ O = 100000/322 = 310.6 mol. Heat released on hydration at night = 310.6 × 16.1 = 5000 kcal. Fuel gas saved = 5000/10000 = 0.5 m ³ = 500 L. Answer: 0500.

Chemistry - Thermochemistry Question with Solution | TestHub

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