Question

Determine the mass in grams of 3.75 x 10^21 atoms of zinc. (the mass of one mole of zinc is 65.39 g)

Answer 1

Answer: The mass in $3.75 \times 10^{21}$ atoms of zinc is 0.405 g.

Explanation:

Given: Atoms of zinc = $3.75 \times 10^{21}$

It is known that 1 mole of every substance contains $6.022 \times 10^{23}$ atoms. So, the number of moles in given number of atoms is as follows.

$Moles = \frac{3.75 \times 10^{21}}{6.022 \times 10^{23}}\\= 0.622 \times 10^{-2}\\= 0.0062 mol$

As moles is the mass of a substance divided by its molar mass. So, mass of zinc (molar mass = 65.39 g/mol) is calculated as follows.

$Moles = \frac{mass}{molar mass}\\0.0062 mol = \frac{mass}{65.39 g}\\mass = 0.405 g$

Thus, we can conclude that the mass in $3.75 \times 10^{21}$ atoms of zinc is 0.405 g.