Answer to Question #327961 in General Chemistry for McQueen

Question

For How Long Must A Current Of 1.5 Ampere Be Passed Through An Aqueous Solution Of A Copper Salt During Electrolysis In Order To Deposit 2.50g Of Copper (cu=63.5)

Answer 1

Solution:

Current, I = 1.5 A

Mass of copper (Cu), m = 2.50 g

Molar mass of copper (Cu), M = 63.5 g/mol

Cu²⁺ + 2e → Cu⁰ (Z = 2)

Faraday's 1^st law: The mass of a substance produced at an electrode during electrolysis is proportional to the number of moles of electrons (the quantity of electricity) transferred at that electrode.

Faraday's 1^st law can be expressed as:

m = (Q × M) / (Z × F)

where:

m = mass of material (g)

M = molar mass of material (g/mol)

Q = I × t = quantity of electricity (C)

Z = number of electrons

F = Faraday constant, 96485 (C mol⁻¹)

Z × F × m = I × t × M

t = (Z × F × m) / (I × M)

t = (2 × 96485 × 2.50) / (1.5 × 63.5) = 5065 s

t = 5065 s

Answer: 5065 seconds