Chapter 9, Problem 126MP

A gaseous hydrocarbon reacts completely with oxygen gas to form carbon dioxide and water vapor. Given the following data, determine ${\text{ΔH°}}_{\text{f}}$ for the hydrocarbon:

${\text{ΔH}}_{\text{rxn}}\text{=}-\text{2044}\text{.5}\text{kJ/mol}$

${\text{ΔH°}}_{\text{f}}{\text{(CO}}_{\text{2}}\text{)}\text{=}-\text{393}\text{.5}\text{kJ/mol}$

${\text{ΔH°}}_{\text{f}}{\text{(H}}_{\text{2}}\text{O)}\text{=}-242\text{kJ/mol}$

Density of ${\text{CO}}_{\text{2}}$ and ${\text{H}}_{\text{2}}\text{O}$ mixture at $\text{1 atm}$ , $\text{200}\text{.°C = 0}\text{.751 g/L}$ The density of the hydrocarbon is less than the density of $\text{Kr}$ at the same conditions.