Styrene, C₈H₈, is one of the substances used in the production of synthetic rubber. When styrene burns in oxygen to form carbon dioxide and liquid water under standard-state conditions at 25°C, 42.62 kJ are released per gram of styrene. Find the standard enthalpy of formation of styrene at 25°C. (Given: $\Delta$H°_f[CO₂(g)] = -393.5 kJ/mol, $\Delta$H°_f[H₂O(l)] = -285.8 kJ/mol, $\Delta$H°_f[H₂O(g)] = -241.8 kJ/mol)

Question

Quizplus · Accepted Answer

The standard enthalpy of formation of styrene can be calculated using the enthalpy change of the combustion reaction and the given enthalpies of formation for CO2 and H2O. The enthalpy change per mole of styrene is calculated by multiplying the given energy release per gram by the molar mass of styrene (104.15 g/mol). Then, using the equation for the enthalpy change of the reaction, the enthalpy of formation of styrene is determined to be approximately 147.8 kJ/mol.

Styrene, C8H8, Is One of the Substances Used in the Production

Styrene, C₈H₈, Is One of the Substances Used in the Production