Question

An open flask containing air is heated from 300 K to 500 K. What percentage of air will escape to the atmosphere, if pressure is kept constant?

• A. 80
• B. 40
• C. 60
• D. 20

Answer 1

The correct option is B

40

$V_1$ = V , $T^1$ =300 K , $T^2$ = 500 K , $V_2$

At constant pressure $V_1{T}_2$ = $V_2{T}_1$

$\therefore$ $V_2$ = $\frac{V_1{T}_2}{T_1}$ = $\frac{V\times 500}{300}=\frac{5V}{3}$

$\therefore$ Volume of aire scaped

= final volume - inital volume

=$\frac{5V}{3}$ -V = $\frac{2V}{3}$

$\therefore$ % of air escaped = $\frac{\frac{2V}{3}}{\frac{5V}{3}}$ $\times$ 100 = 40%