Chapter 9, Problem 9.74SP

Interpretation Introduction

Interpretation:

The amount of heat evolved or absorbed needs to be determined. Whether the reaction is exothermic or endothermic needs to be determined.

Concept introduction:

From mass and molar mass, the number of moles of a substance can be calculated as follows:

$n=\frac{m}{M}$

Here, m is mass and M is molar mass.

If enthalpy change for 1 mol of substance is given, the same for different number of moles of substance can be calculated by simply multiplying the number of moles with the enthalpy change. If the change in enthalpy is negative, the reaction is exothermic in nature and if it is positive, the reaction is endothermic in nature.