Question

Dal lake has water $8.2\times {10}^{12}$ litre approximately. A power reactor produces electricity at the rate of $1.5\times {10}^6$ coulomb per second an appropriate voltage. How many years would it take to electrolyse the lake?

• A. 3 million year
• B. 4.1 million year
• C. 1.9 million year
• D. None of these

Answer 1

The correct option is C 1.9 million year

At anode: $2H_{2}O\to 4H^{+}+O_2+4e^{-}$

At cathode: $2H_{2}O+2e^{-}\to H_2+2O{H}^{-}$

Net reaction: $2H_{2}O\to 2H_2+O_2$

$4Faraday\to 2mole{H}_{2}O=36g=36mL$

$1mL{H}_{2}O\to \frac{4\times 96500}{36}Faraday$

$8.2\times {10}^{15}mL{H}_{2}O....\frac{4\times 96500}{36}\times 8.2\times {10}^{15}Faraday$

$t=\frac{4\times 96500\times 8.2\times {10}^{15}}{36\times 1.5\times {10}^{-6}}sec=5.861\times {10}^{13}sec$

$=1.858\times {10}^6$ years

So, the correct option is $C$