Question

3. How many atoms of H are present in 24.3 moles of H2O?

Answer 1

Answer:

$2.96 \times 10^{25}$ atoms.

Explanation:

• 1 mol of $H_2O$ has $2 N_A = 1.20 \times 10^{24}$ atoms of H inside. This is because in one mol of the molecule there are two atoms of hydrogen.  
• 24.3 mol of $H_2O$ has $x$ atoms of Hydrogen inside.

$x = 1.2044 \times 10^{24} \times 24.3 = 2.96 \times 10^{25}$

Extra:

• $N_A$ is the Avogadro's Number, which is equal to $6.022 \times 10^{23}$ atoms, the value of one mol.