Calculate the mass of a sample of cobalt containing 3.31x10^22 atoms

Mass = 3.24 g

Explanation:

Given data:

Number of atoms of cobalt = 3.31 × 10²² atoms

Mass of cobalt = ?

Solution:

We will calculate the number of moles of cobalt first.

1 mole contain 6.022× 10²³ atoms

3.31 × 10²² atoms  × 1 mol / 6.022× 10²³ atoms

0.0549 mol

Mass of cobalt:

Mass = number of moles × molar mass

Mass = 0.0549 mol × 58.93 g/mol

Mass = 3.24 g