# What is the mass of 4.75 * 10^21 platinum atoms?

Feb 13, 2016

$1.54 g$

#### Explanation:

$6.023 \times {10}^{23}$ Pt atoms constitutes $1$ mole of Pt.

Hence, by ratio and proportion, $4.75 \times {10}^{21}$ atoms constitutes $0.0078864$ moles.

Hence the mass will be the product of the moles with the molar mass,

$m = n \times {M}_{r}$

$= 0.0078864 m o l \times 195.1 g / m o l$

$= 1.54 g$.