Answer to Question #237671 in Chemistry for Nas

Question

A (Ni+2) solution is electrolyzed using a current of 1.25A. What mass of (Ni0 )

plates out in 30 minutes.

Answer 1

Solution:

Current, 1.25 A

Time, t = 30 min = 1800 s

Quantity of electricity, Q = I × t = (1.25 A) × (1800 s) = 2250 C

Mass of nickel (Ni), m = ??? g

Molar mass of nickel (Ni), M = 58.69 g/mol

Ni²⁺ + 2e → Ni^o (2 electrons)

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 = quantity of electricity (C)

Z = number of electrons

F = Faraday constant, 96485 (C mol^-1)

 

Thus:

m(Ni) = (2250 C × 58.69 g/mol) / (2 × 96485) = 0.684 g

Mass of nickel (Ni) = 0.684 g

Answer: 0.684 g