Question

At. N.T.P. 28 g of Nitrogen occupies 22.4 litres. What is the mass of 5.6 liters of Nitrogen at 38 cm of Hg pressure and ${273}^{0}C$ temperature

• A. $7g$
• B. $48g$
• C. $1.87g$
• D. $1.5g$

Answer 1

The correct option is C $1.87g$

Given,

At, NTP (293 K, 76 cm Hg): Volume,$V=22.4L$ ,Number of mole, $n_1=1mole$

$273{}^{o}C=546K$

At (38 cm, 546 K): Volume $V=5.6L$

From ideal gas equation.

$PV=nRT$

$\frac{P_1{V}_1}{P_1{V}_2}=\frac{n_{1}R{T}_1}{n_{2}R{T}_2}$

$\Rightarrow \frac{76\times 22.4}{38\times 5.6}=\frac{1\times R\times 293}{n_{2}R\times 546}$

$\Rightarrow n_2=0.67mole$

$1mole{N}_2=28g$

$0.067mole{N}_2=28\times 0.067=1.87g$

Hence, mass of nitrogen is $1.87g$