Question

The enthalpy of combustion of C${}_6$H${}_6$ $\left(l\right)$ is -3250 kJ. When 0.39 g of benzene is burnt in excess of oxygen in an open vessel, the amount of heat liberated is:

• A. 16.25 KJ
• B. 33.50 KJ
• C. 32.5 KJ
• D. 65 K J

Answer 1

The correct option is A 16.25 KJ

0.39 g corresponds to $=\frac{39}{100\times 78}$ moles
$=5\times {10}^{-3}$ moles
$\therefore$ heat liberated $=5\times {10}^{-3}$ x 3250 KJ
$=3.250\times 5$ KJ
$=$ 16.250 KJ