Q. In the combustion of 2.0 g of methane, 25 kcal heat is liberated. Heat of combustion of methane would be
A) 150 kcal
B) 200 kcal
C) 250 kcal
D) 350 kcal
Explanation
(b)
$CH_{4} + 2O_{2} \rightarrow {CO}_{2} + 2H_{2}O$
Molecular weight of $CH_{4} = 12 + 4 = 16$
$\therefore\$On the combustion of 2.0 g of methane = 25.0 kcal
$\therefore\$On the combustion of 16.0 g methane $= \frac{25 \times 16}{2} = 200$ kcal
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.