Question

An open flask contains air at $27^{0}C$. At what temperature should it be heated so that 1/3^rd of air present in it goes out?

• A. $177^{0}C$
• B. $100^{0}C$
• C. $300^{0}C$
• D. $150^{0}C$

Answer 1

Answer: (A)

$177^{0}C$

Answer 2

: Let initial number of moles of air at $27^{0}C$ (300k) =n

At temperature T K, the no. of moles left $= n - \frac{n}{3} = \frac{2n}{3}$

At constant pressure and volume, $n_{1}T_{1} = n_{2}T_{2}$

$n \times 300 = \frac{2n}{3} \times T \Rightarrow T = 450kor177^{0}C$