Question

A vessel has $N_2$ gas and water vapours at a total pressure of 1 atm. The partial pressure of water vapours is 0.3 atm. The contents of this vessel are transferred to another vessel having one-third of the capacity of original volume, completely at the same temperature the total pressure of this system in the new vessel is

• A. 3.0 atm
• B. 1.0 atm
• C. 3.33 atm
• D. 2.4 atm

Answer 1

The correct option is D 2.4 atm

$P_{N_2}+P_{H_{2}O}=1atm$

$\therefore P_{H_{2}O}=0.3atm$

$\therefore P_{N_2}$ = 0.7 atm in 1st vessel.

Now new pressure of $N_2$ in another vessel may be calculated as

$P_1{V}_1=P_2{V}_2$

$\therefore 0.7\times V_1=P_2\times \frac{V_1}{3}$atm

$\therefore P_{N_2}$ = 2.1 atm

$\Rightarrow P_{H_{2}O}=0.3$atm

$P_T=2.1+0.3=2.4$ atm

$P_{H_{2}O}$ remains constant at constant temperature