Question

The density of $Cu$ is $8394g.c{m}^{-3}$. The quantity of electricity needed to plate an area $10cm\times 10cm$ to a thickness of ${10}^{-2}$ cm using $CuS{O}_4$ solution would be:

• A. $13586$C
• B. $27172$C
• C. $40758$C
• D. $20348$C

Answer 1

The correct option is A $13586$C

work done in isothermal process = $2.303RTlog{p}_1/p_2$

$W=2.303log{p}_1/p_2.RT$

$W=56.27log6.977$

$W=47.46$ L atm (ans)

amount of cu deposited = $\frac{massofcudeposited}{molarmassofcu}$

$=\frac{(8.94\times 10\times 10\times {10}^{-2}c{m}^3)}{63g/mol}=0.142mol$.

now, quantity required = $2\times 96500\times 0.142=13586C$ (option (A))