Chapter 4, Problem 4.18NP

Interpretation Introduction

Interpretation:

The enthalpy of dissolution of sodium sulfate needs to be calculated from calorimetry and thermochemical data.

Concept Introduction:

Chemical reactions in general involve exchange of heat between the system (reactants and products) and the surroundings. The heat (q) absorbed or evolved is given as: $\text{q = m ×c×ΔT ------(1)}$

Here, m and c are the mass and specific heat capacity of the substance

ΔT = change in temperature

The standard enthalpy change for a reaction ${\text{ΔH}}^{\text{0}}$ is given in terms of the difference in the standard enthalpy of formation of the products and that of reactants.

i.e. $\Delta {\text{H}}^0\text{ = }{\displaystyle \sum {\text{n}}_{\text{p}}{\text{ΔH}}_{\text{f}}^{\text{0}}}\text{(products) - }{\displaystyle \sum {\text{n}}_{\text{r}}{\text{ΔH}}_{\text{f}}^{\text{0}}}\text{(reactants) ------(2)}$

Here, n_p and n_r are the number of moles of the products and reactants