NTA Abhyas JEE Main2020ChemistryElectrochemistryPractice
A current of 5 .0 A flows for 4 .0 h through an electrolytic cell containing a molten salt of metal M. This results in deposition of 0 .25 mol of the metal M at the cathode. The oxidation state of M in the molten salt is + x . the value of ' x ' is ( 1 Faraday = 96000 C m o l - 1 )
Correct answer
3
Step-by-step solution
I = 5.0 A , t = 4.0 h Moles of metal deposited = 1 4 Q = 5.0 × 4 × 60 × 60 coulombs Charge in faradays Q = 5 × 4 × 60 × 60 96000 = 0.75 F 1 4 moles of metal will be deposited by 3 4 F charge required So, for 1 mole, 3 4 × 4 = 3 F Oxidation = + 3