Question

Air is filled at 60⁰C in a vessel of open mouth. The vessel is heated to a temperature T so that 1 / 4^th part of air escapes. Assuming the volume of vessel remaining constant, the value of T is

• A. 80⁰C
• B. 444⁰C
• C. 333⁰C
• D. 171⁰C

Answer 1

Answer: (D)

171⁰C

Answer 2

$M_{1} = M$, $T_{1} = 60 + 273 = 333K$, $M_{2} = M - \frac{M}{4} = \frac{3M}{4}$ [As 1 / 4^th part of air escapes]

If pressure and volume of gas remains constant then MT

= constant

∴ $\frac{T_{2}}{T_{1}} = \frac{M_{1}}{M_{2}} = \left( \frac{M}{3M/4} \right) = \frac{4}{3}$ ⇒ $T_{2} = \frac{4}{3} \times T_{1} = \frac{4}{3} \times 333 = 444K = 171{^\circ}C$