Question 442: Current Electricity

Question

The nagative $Zn$ pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by $0.13g$ in $30$ minutes. If the electrochemical equivalent of $Zn$ and $Cu$ are $32.5$ and $31.5$ respectively, the increase in the mass of the positive $Cu$ pole in this time is

Accepted Answer

According to Faraday's first law of electrolysis $m = z 	imes q$
For same $q,$ $\,\,\,\,\,\,\,\,\,$ $m \propto Z$
$	herefore$ ${{{m_{Cn}}} \over {{m_{Zn}}}} = {{{Z_{Cu}}} \over {{Z_{Zn}}}}$
$ \Rightarrow {m_{Cu}} = {{{Z_{Cu}}} \over {{Z_{Zn}}}} 	imes {m_{Zn}}$
$ = {{31.5} \over {32.5}} 	imes 0.13 = 0.126\,g$

Answer

$0.180$ $g$

Answer

$0.141$ $g$

Answer

$0.126$ $g$

Answer

$0.242$ $g$

Current Electricity

The nagative Zn pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by 0.13g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is

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