JEE PYQ: States Of Matter Question 3
Question 3 - 2021 (17 Mar Shift 2)
The number of chlorine atoms in 20 mL of chlorine gas at STP is ____ $\times 10^{21}$. (Round off to the Nearest Integer). [Assume chlorine is an ideal gas at STP; $R = 0.083$ L bar $\text{mol}^{-1} \text{K}^{-1}$, $N_A = 6.023 \times 10^{23}$]
Show Answer
Answer: 1
Solution
$PV = nRT$; $n = \frac{PV}{RT} = \frac{1 \times 0.02}{0.083 \times 273}$. Number of $\text{Cl}_2$ molecules $= 5.3 \times 10^{20}$. Number of Cl atoms $= 1.06 \times 10^{21} \approx 1 \times 10^{21}$.
BETA
