Question

In a copper voltameter, cathode plate is circular its radius is $2.5$ cm, current is $2.5$A. $1$mm layer is to be deposited on both sides. Find the time required density is $9$ gm per cc.

Answer 1

Volume of $Cu$ to be deposited $=2\times 3.14\times {\left(2.5\right)}^2\times \left(0.1\right)$

$(2\times area\times thickness)$ $=3.925{cm}^3$

$\therefore density=\frac{mass}{V}$

$mass=9\times 3.925=35.325g$

moles of $Cu=\frac{35.325}{63}=0.56mol$

${Cu}^{2+}+2e^{-}\to Cu$

$Faraday=2\times 0.56=1.12F$

$Faraday=\frac{change}{96500}=\frac{2.5\times t}{96500}=1.12$

$t=42950s$