Question

How many H2O molecules are in 183.2 grams of H20 gas?

Answer 1

Answer: There are $61.24 \times 10^{23}$ molecules present in 183.2 grams of $H_{2}O$ gas.

Explanation:

Given: Mass = 183.2 g

Number of moles is the mass of substance divided by its molar mass.

As molar mass of water is 18 g/mol. Therefore, moles of $H_{2}O$ are calculated as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{183.2 g}{18 g/mol}\\= 10.17 mol$

According to the mole concept, there are $6.022 \times 10^{22}$ molecules present in one mole of a substance.

Hence, molecules present in 10.17 moles are calculated as follows.

$10.17 mol \times 6.022 \times 10^{23}\\= 61.24 \times 10^{23}$

Thus, we can conclude that there are $61.24 \times 10^{23}$ molecules present in 183.2 grams of $H_{2}O$ gas.