Question

At a pressure of P atm and temperature of T K. 3.6 g of an ideal gas was injected into a bulb of internal volume 8 L. The bulb was then placed in a thermostat maintained at (T + 15) K and 0.6 g of the gas was let off to maintain the original pressure. What is correct value of T and P if molar mass of gas is 44 g/mol.

• A. P = 0.062 atm, T = 50 K
• B. P = 0.62 atm, T = 75 K
• C. P = 0.062 atm, T = 75 K
• D. P = 6.2 atm, T = 75 K

Answer 1

Answer: (C)

$P\times V=\frac{3.6}{44}\times R\times T$ ...(i)
$P\times V=\frac{3}{44}R\left(T+15\right)$ ...(ii)
Equation (i) = (ii)
$3.6T=3T+45$
$0.6T=45$
$T=\frac{45}{0.6}\times \frac{450}{6}=75$
$\to$ From $PV=nRT\Rightarrow$
$P\times 8=\frac{3.6}{44}\times 0.0821\times 75$
$P=0.062$