Question

Using the following thermochemical equation, determine the amount of heat produced per kg of CO2 formed during the combustion of benzene (C6H6).
2 C6H6(l) + 15 O2(g) → 12 CO2(g) + 6 H2O(g) ΔH°rxn = -6278 kJ

Answer 1

Answer:  12033 kJ of heat produced per kg of $CO_2$ formed during the combustion of benzene

Explanation:

The balanced chemical equation for combustion of benzene is :

$2C_6H_6(l)+15O_2(g)\rightarrow 12CO_2(g)+6H_2O(g)$  $\Delta H°rxn$ = -6278 kJ

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and $\Delta H$ for the reaction comes out to be negative.

$\text{Moles of }CO_2=\frac{\text{given mass}}{\text{Molar Mass}}=\frac{1000g}{44g/mol}=23mol$      (1kg=1000g)

According to stoichiometry :

12 moles of $CO_2$ on combustion produce heat = 6278 kJ

Thus 23 mole of $CO_2$ on combustion produce heat =$\frac{6278}{12}\times 23=12033kJ$

Thus 12033 kJ of heat produced per kg of $CO_2$ formed during the combustion of benzene