The enthalpy of combustion of C 8 H 6 is - 3250 kJ when 0.39 g of C 6 H 6 is burnt in excess of oxygen in an open vessel, the amount of heat evolved is :

Question

The enthalpy of combustion of C 8 H 6 is - 3250 kJ when 0.39 g of C 6 H 6 is burnt in excess of oxygen in an open vessel, the amount of heat evolved is : (A) 8.32 kJ (B) 12.36 kJ (C) 16.25 kJ (D) 20.74 kJ

Tardigrade Admin · Accepted Answer

Combustion of benzene can be represented as follows

C_{6} H_{6} + O_{2} ⟶ 6 C O_{2} + H_{2} O + 3250 k J

78 g

of

C_{6} H_{6}

produce

3250 k J

heat

18

will produce

\frac{3250}{78} k J

heat

39 g

will produce

= \frac{3250}{78} \times 0.39 k J

= 16.25 k J

heat is liberated
Enthalpy of combustion is the amount of heat liberated when one mole of a substance is burnt in excess of air.

Q. The enthalpy of combustion of C8​H6​ is - 3250kJ when 0.39g of C6​H6​ is burnt in excess of oxygen in an open vessel, the amount of heat evolved is :

8.32 kJ

12.36 kJ

16.25 kJ

20.74 kJ

Q. The enthalpy of combustion of $C_{8} H_{6}$ is - $3250 k J$ when $0.39 g$ of $C_{6} H_{6}$ is burnt in excess of oxygen in an open vessel, the amount of heat evolved is :