Question

The weight of 350 mL of a diatomic gas at
0°C and 2 atm pressure is 1 gr. The weight in
gr. of one atom at NTP is
(A) 2.64 x 10-23 gr
(B) 2.64 x 10-22gr
(C) 5.28 x 10-23 GT
(D) 0.82 x 10-22 gr​

Answer 1

Given :-

Volume, V = 350 mL= 0.35L

Temperature, T = 0°C = 273 K

Pressure, P = 2 atm

Weight of gas, W = 1g

To Find :-

Weight in gram of one atom at NTP.

Solution :-

We know :-

$\bf PV=nRT$

Substitute the values :-

$: \implies \sf \ 2 \times0 .35 = n \times 0.0821 \times 273$

$: \implies \sf n = \dfrac{2 \times 0.35 } {0.0821 \times 273}$

$: \implies \sf \ n = \dfrac{0.7}{22.41}$

$: \implies \sf n = 0.0312$

Given that :-

Mass of 0.312 mol = 1 g

So,

Mass of one mol = 1/0.0321 ≈ 32 g

It is given gas is diatomic .

So,

Mass of one atom = 16g

Weight of one atom of gas :-

$: \implies \sf \dfrac{16}{6.022 \times 10^{23} }$

$: \implies \sf 2.65\times 10^{-23} g$