Answer:
Time take to deposit Ni is 259.02 sec.
Step-by-step explanation:
Given:
Current
A
Faraday constant

Molar mass of Ni

Mass of Ni
g
First find the no. moles in Ni solution,
Moles of Ni

mol
From the below reaction,
⇆

Above reaction shows "1 mol of
requires 2 mol of electron to form 1 mol of
"
So for finding charge flow in this reaction we write,

Charge flow
C
For finding time of reaction,

Where
charge flow


sec
Therefore, time take to deposit Ni is 259.02 sec.