Question

The u.S. Mint produced pure silver quarter commemorative coins in 1992, each coin weighing 5.67 g. How many silver atoms are present in each coin?

Answer 1

Mass of each silver coin = 5.67 g

Molar mass of silver = 107.87 g/mol

Calculating the moles of silver from given mass and molar mass of silver:

$5.67 g Ag*\frac{1molAg}{107.87g} =0.0526molAg$

Calculating the atoms of silver in 0.05260 mol using the conversion factor, $1mol=6.022*10^{23}atoms$:

$0.05260 mol*\frac{6.022*10^{23}atoms }{1mol} =3.17*10^{22}atoms$

Therefore, $3.17*10^{22}$atoms of silver are present in each coin.