Faraday's first law of electrolysis: Amount of a substance deposited or liberated on respective electrode is directly proportional to the quantity of electricity following through the circuit.
`W prop Q rArr W= ZQ`
W= Zit where Z= electrochemical equivalent of the substance.
(i) In order to deposit or liberate 1 mole of substance, integeral no of Faradays are required.
(ii) In order to deposit one gram equivalent of substance, 1 Faraday electricity is required.
Current efficiency `= ("Actual yield")/("Theoritical yield") xx 100%`
For the reaction, `2CH_(3)COO^(-) rarr C_(2)H_(6)(g) + 2CO_(2)(g) + 2e^(-)`. If current of 20A is passed for 965sec, volume of liberated gases measured at NTP is found to be 3.36 lit, then calculate current efficiency of the reaction

Options

A. `60%`
B. `70%`
C. `50%`
D. `75%`

Answer

C

Explanation

Total moles of gas `=C_(2)H_(6) + 2CO_(2)=3` moles
Number of Faraday `= (20 xx 965)/(96500)= 0.2F eta = ((3.36)/(22.4))/(0.3)xx 100% = 50%`