Q. When 1 kg of hydrogen forms water, $34 \times 10^{6}\ $cal of heat is liberated. If ECE of hydrogen is (1/96500,000)kg $C^{- 1}$, then the minimum voltage requird for decomposition of water is
A) 0.75 V
B) 3.0 V
C) 1.5 V
D) 6.0 V
Explanation
(c) $q = \frac{m}{z} = \frac{1}{(1/96500,00)} = 96500,000$ C
$V = \frac{H}{q} = \frac{34 \times 10^{5} \times 4.2}{96500,000} = 1.48 = 1.5$V.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.