Verified Solution • 2025–26 Session
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QNEET-2024-Ch-6: NEET 2024 Chemistry - Class 12 NEET-2024-Ch-6 Solution: Mass in grams of copper deposited by passing \(9.6487\ {A}\)…
Mass in grams of copper deposited by passing current through a voltmeter containing copper sulphate solution for 100 seconds is (Given: Molar mass of Cu: ) 3.15 g 0.315 g 31.5 g 0.0315 g
Multiple Choice Options
- A 3.15 g
- B 0.315 g
- C 31.5 g
- D 0.0315 g
Step-by-Step Verified Solution
The mass of copper deposited when passing an electric current through a copper sulphate solution can be calculated using Faraday's laws of electrolysis. The first law states that the amount of a substance deposited or liberated at an electrode during electrolysis is proportional to the amount of electricity (charge) passed through the electrolyte.
To find the mass of copper deposited, we use the formula:
m = M _ I _ t n _ F
Where:
m is the mass of the substance deposited (in grams),
M is the molar mass of the substance (in g/mol),
I is the current (in amperes, A),
t is the time electricity is passed through the solution (in seconds),
n is the number of moles of electrons required to deposit or dissolve 1 mole of the substance (valence number, which is 2 for copper in copper sulphate solution as copper ions are Cu 2 + ),
F is the Faraday constant, approximately 96487 C / mol of electrons.
Given:
M = 63 g / mol
I = 9.6487 A
t = 100 s
n = 2
F = 96487 C / mol
Substitute these values into the formula:
m = 63 g / mol _ 9.6487 A _ 100 s 2 _ 96487 C / mol
Calculate the value of m :
m = 63 _ 9.6487 _ 100 2 _ 96487
m = 60828.21 192974
m � 0.315 g
Hence, the mass of copper deposited is approximately 0.315 g, making Option B the correct answer.