Question

If $N_A$ is Avogadro's number, then the number of oxygen atom in one g-equivalent of oxygen is

• A. $N_A$
• B. $N_A/2$
• C. $N_A/4$
• D. $2N_A$

Answer 1

Answer: (B)

$G.M.M.$ of $O_2=32g$
Eq. mass $=\frac{\text{At . mass of O}}{\text{valency}}=\frac{16}{2}=8$
$32g$ of oxygen contain oxygen atoms $=2\times N_A$
$\therefore 8g$ of oxygen contains oxygen atom
$=\frac{2\times N_A}{4}=N_A/2$