Chapter 9, Problem 9.93SP

Interpretation Introduction

Interpretation:

This is to be shown that given equation (1) and (2) gives the net equation. Also, the value of $\Delta {{\rm H}}^0$ for the net equation needs to be determined.

$\begin{array}{l}\left(\text{1}\right){\text{ CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH }\left(\text{l}\right){\text{ + ½ O}}_{\text{2}}\left(\text{g}\right)\to {\text{CH}}_{\text{3}}\text{CHO }\left(\text{g}\right){\text{ + H}}_{\text{2}}\text{O }\left(\text{l}\right)\text{= - 174}\text{.2 kJ}\\ \left(\text{2}\right){\text{ CH}}_{\text{3}}\text{CHO }\left(\text{g}\right){\text{ + ½ O}}_{\text{2}}\left(\text{g}\right)\to {\text{CH}}_{\text{3}}\text{COOH }\left(\text{l}\right)\text{= - 318}\text{.4 kJ}\\ \left(\text{Net}\right){\text{ CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH }\left(\text{l}\right){\text{ + O}}_{\text{2}}\left(\text{g}\right)\to {\text{CH}}_{\text{3}}\text{COOH }\left(\text{l}\right){\text{ + H}}_{\text{2}}\text{O }\left(\text{l}\right)\text{=?}\end{array}$

Concept introduction:

The enthalpy of a reaction is a state function. The value of change in enthalpy is same and it does not depend on the path followed for conversion of reactants to products. Due to this, the sum of change in enthalpy for the individual steps in the reaction is equal to the overall enthalpy change of the reaction.