Question

$1.25gN{H}_3$ contains how many atoms?

• A. $10^{23}$
• B. $2\times 10^{23}$
• C. $6\times 10^{13}$
• D. $4\times 10^{23}$

Answer 1

Answer: (B)

No. of atoms = No. of gram molecular weight $\times 6.02\times 10^{23}\times$ atomicity
No. of atoms in $1.25g$ of $N{H}_3$
$=\frac{1.25}{17}\times 6.02\times 10^{23}\times 4$
$=2.2\times 10^{23}$