Question

If one mole of $H_2$ is compressed from 10 $L$ to 7.5 $L$ at constant temperature, what happens to the gas pressure?

• A. It increases by 25%
• B. It decreases by 25%
• C. It increases by 33%
• D. It increases by 50%
• E. None of the above

Answer 1

The correct option is C It increases by 33%

At constant temperature $P_1{V}_1$$=$$P_2{V}_2$

or $P_1\ast 10$$=$$P_2\ast 7.5$

or $P_2$$=$$4\ast P_1/3$

or $(P_2$-$P_1$)/$P_1$$=$ $1/3$

so percentage increase $=$$100/3$$=$$33.33$