Q. Which of the following pairs contains equal number of atoms?
A) 11.2 cc (STP) of nitrogen and 0.015 g of nitric oxide
B) 22.4 L (STP) of nitrous oxide and 22.4 L of nitric oxide
C) 1 millimole of HCL and 0.5 millimole of $H_{2}S$
D) 1 mole of $H_{2}O_{2}$ and 1 mole of $N_{2}O_{4}$
Explanation
(a)
Number of atoms in $N_{2} = \frac{11.2 \times 10^{- 3} \times 6.023 \times 10^{23} \times 2}{22.4}$
$= 6.023 \times 10^{20}$
Number of atoms in NO $= \frac{0.015 \times 2 \times 6.023 \times 10^{23}}{30}$
$= 6.023 \times 10^{20}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.