Question
The electrochemical equivalent of a metal is 3.3 × 10−7 kg per coulomb. The mass of the metal liberated at the cathode when a 3 A current is passed for 2 seconds will be
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19.8 × 10−7 kg
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9.9 × 10−7 kg
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6.6 × 10−7 kg
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1.1 × 10−7 kg
Solution
A.
19.8 × 10−7 kg
Mass of substance liberated at cathode m = zit
where, z = electro-chemical equivalent = 3.3× 10-7 kg/C
i = current flowing = 3A.
t = 2 sec
∴ m = 3.3× 10-7× 3× 2
= 19.8× 10-7 kg
