A metal surface of 100 cm ^ 2 area has to be coated with nickel...

One equivalent of substance deposited for $96500C$(one Faraday).

$i \times t$ Columbus of charge can be utilised to get $wg$ of substance.

Millimoles of $Ni$ coated

$= \dfrac{( 2x ) 100}{96500 \times 2}$

$= \dfrac{10x}{965}$

Mass of $Ni = \left(\dfrac{x}{965}\right)600$

$= \dfrac{600x}{965}mg$

Volume$= \dfrac{60x}{965} \times {10}^{- 3}{cm}^{3}$

$= 100 \times {10}^{- 4}$

$⇒ x = 0 . 1608 \times {10}^{3}$

$\approx 161$