Question

Calculate the enthalpy of combustion of acetic acid if it's enthalpy of formation is -486. The enthalpy of formation of co2 and h2o are -394 and -286

Answer 1

Answer:

Enthalpy of combustion of acetic acid is -874 kJ /mol

Explanation:

Balanced chemical equation for the combustion of acetic acid is

     $CH_{3} COOH+2O_{2} (g)$  →   $2CO_{2(g)} + 2H_{2}O_{(l)}$

Enthalpy of combustion is the difference between the sum of enthalpy of formation of products and the sum of enthalpy of formation of reactants.

i.e., Δ$H^{0} =$ ΣΔH$^{0}_{f(products)} -$ ΣΔH$^{0}_{F(reactants)}$

Enthalpy of formation of $CO_{2}$ = -394 KJ/mol

Enthalpy of formation of $H_{2}O$ = -286KJ/mol

Enthalpy of combustion of acetic acid , Δ$H^{0}$ = ((2×-394)+(2×-286)) - (-486)

                                                                         = -874 KJ/mol