Q. When 1 g hydrogen (ECE=$1.044 \times 106^{- 8}\ kg\ C^{- 1})$ forms water, 34 kilo cal heat is liberated. The minimum voltage required to decompose water is
A) 0.75 V
B) 1.5 V
C) 3.0 V
D) 4.5 V
Explanation
(b) Here , $m = 1\ g = p^{- 3}\ kg;$
$\ z = 1.044 \times 10^{- 8}\ kg\ C^{- 1}$
$\ H = 34\ k\ cal. = 34 \times 1000 \times 4.2\ J$
$\ q = \frac{m}{z} = \frac{10^{- 3}}{1.044 \times 10^{- 8}} = \frac{10^{5}}{1.044}$ C
and$\ V = \frac{H}{q} = \frac{34 \times 1000 \times 4.2}{(10^{5}/1.044)} = 1.5$ V.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.