Chapter 6, Problem 6.116QP

Ethylene glycol, HOCH₂CH₂OH, is used as antifreeze. It is produced from ethylene oxide, C₂H₄O, by the reaction

${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}\text{O}(g)+{\text{H}}_{\text{2}}\text{O}(l)\to {\text{HOCH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{OH}(l)$

Use Hess’s law to obtain the enthalpy change for this reaction from the following enthalpy changes:

$\begin{array}{c}2{\text{C}}_{\text{2}}{\text{H}}_{\text{4}}\text{O}(g)+5{\text{O}}_2(g)\to 4{\text{CO}}_2(g)+4{\text{H}}_{\text{2}}\text{O}(l);\\ \Delta H=-2612.2\text{kJ}\\ {\text{HOCH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{OH}(l)+\frac{5}{2}{\text{O}}_2(g)\to 2{\text{CO}}_2(g)+3{\text{H}}_{\text{2}}\text{O}(l);\\ \Delta H=-1189.8\text{kJ}\end{array}$