Question

5. How many grams of cobalt are in 1.52 x 1024 atoms of cobalt?

Answer 1

149 g of cobalt are present in 1.52 x $10^{24}$ atoms of cobalt.

Explanation:

One mole of an atom is equal to the Avagadro number of the atom.

              $1 \ mol \ of \ Co = 6.023\times10^{23} atoms\ of \ Co$

The number of atoms per mol is divided by the given atoms of Cobalt.

                =  $(1.52 \times 10^{24}) \times$ $\frac{1 \ mol\ Co}{6.023 \times10^{23}\ atoms\ Co}$

                = 2.52 mol of Co

To covert, the moles into grams multiply the mole value by its molar mass

The Molar mass of Cobalt is 58.93

                = 2.52 $\times$ 58.93

                = 149 g.