Question

Calcium oxide reacts with water to produce calcium hydroxide and 65.2 kJ of heat in the following reaction. CaO (s) + H2O (l) → Ca(OH)2 (s) ΔH = - 65.2 kJ How much heat is released when 100.0 g of calcium oxide reacts with excess water?

Answer 1

Answer:

116.43 kJ of heat is released when 100.0 g of calcium oxide reacts with excess water.

Explanation:

$CaO (s) + H_2O (l)\rightarrow Ca(OH)_2 (s)$ , ΔH = -65.2 kJ

Mass of calcium oxide = 100.0 g

Moles of calcium oxide = $\frac{100.0 g}{56 g/mol}=1.7857 mol$

According to reaction, 1 mole of calcium oxide on reaction with water gives off  65.2 kilo Joules of heat. Then 1.7857 moles of calcium oxide will give:

$\frac{65.2}{1}\times 1.7857 kJ=116.43 kJ$

116.43 kJ of heat is released when 100.0 g of calcium oxide reacts with excess water.