In order to plate a steel part having a surface area of 200 in.2 with a 0.002 in.-thick layer of nickel: (a) how many atoms of nickel are required? (b) How many moles of nickel are required?

Answer :

(a) The number of atoms of nickel required are,

(b) The moles of nickel are, and 0.9944 mol

Explanation : Given,

Area =

Conversion used :

Thickness = 0.002 in  =  0.002 × 2.54 = 0.00508 cm

Conversion used : (1 in = 2.54 cm)

First we have to calculate the volume of nickel.

Volume of nickel = Area × Thickness

Volume of nickel =

Volume of nickel =

Now we have to calculate the mass of nickel.

Mass of nickel = Density of nickel × Volume of nickel

Density of nickel = 8.91 g/cm³

Mass of nickel = 8.91 g/cm³ × 6.55 cm³

Mass of nickel = 58.36 g

Now we have to calculate the moles of nickel.

Molar mass of nickel = 58.69 g/mol

Now we have to calculate the number of atoms of nickel are required.

As, 1 mole of nickel contains atoms of nickel

So, 0.9944 mole of nickel contains atoms of nickel

Thus, the number of atoms of nickel required and moles of nickel are, and 0.9944 mol respectively.

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