Question

At constant pressure, a sample of helium gas has a volume of $800ml$ at ${27}^{o}C$. Calculate the percentage increase in volume, if temperature is ${90}^{0}C$.

• A. $45$%
• B. $21$%
• C. $66.7$%
• D. $100$%

Answer 1

The correct option is B $21$%

$V\propto T$ at constant pressure

$\therefore \frac{V_2}{V_1}=\frac{T_2}{T_1}⟹\frac{V_2}{800ml}=\frac{363K}{300K}⟹V_2=968ml$

Percent increase in volume $=\frac{V_2-V_1}{V_1}\times 100\%=\frac{168}{800}\times 100\%=21\%$

Hence, the correct option is B.