Question

A current of 0.5 ampere is passed for 30 minutes through a voltameter containing copper sulphate solution. Calculate the weight of copper deposited at the cathode. (At. wt. of Cu = 63.6u).​

Answer 1

Answer:

5 amperes is 5 coulombs per second, 5C/s

So the total charge in 30 minutes is Q = 5C/s x 30min x 60s/min = 9000C

Then the number of moles of copper plated out (n) is:

n = Q/zF where z is the number of electrons in the half-cell reaction (in this case, 2) and F is the Faraday constant = 96,485/mol

So, n = 9000/(2x96485) = 0.0466mol

And this is 63.546 x 0.0466 = 2.96g

So 2.96 grams are plated deposited at the cathode.

Explanation: