Chapter 12.5, Problem 12.5.2SR

Interpretation Introduction

Interpretation:

The energy given off when $1.00g$ of steam cools down to room temperature $25^{°}C$ from ${100}^{°}C$ has to be determined and the correct answer has to be chosen from the following options –

1. (a) $0.326\text{ kJ}$ (b) $\text{316 kJ}$ (c) $\text{2}\text{.58 kJ}$ (d) $\text{48}\text{.9 kJ}$  (e) $\text{22}\text{.1 kJ}$

Concept Introduction:

• Specific heat of a substance refers to the quantity of heat per unit mass of substance that rises the temperature of the substance by one degree Celsius. The quantity of heat added and the specific heat is related as follows –

$\begin{array}{l}\text{q = m}\times \text{s}\times \Delta \text{T}\\ \text{where q = heat added}\\ \text{ m = mass of the substance}\\ \text{ s = specific heat of the substance}\\ \Delta \text{T = change in Temperature}\\ \end{array}$

• Molar heat of vaporization is the heat energy required to boil one mole of a substance at its boiling point.
• Molar heat of fusion is the heat energy required to freeze one mole of the substance at its melting point.