Question

Two gases occupy two containers $A$ and $B$ the gas in $A$, of volume $0.10\, m ^{3}$, exerts a pressure of $1.40\, MPa$ and that in B of volume $0.15\, m ^{3}$ exerts a pressure $0.7\, MPa$. The two containers are united by a tube of negligible volume and the gases are allowed to intermingle. Then if the temperature remains constant, the final pressure in the container will be (in $MPa$)

• A. 0.70
• B. 0.98
• C. 1.40
• D. 210

Answer 1

Answer: (B)

As the quantity of gas remains constant $\mu_{A}+\mu_{B}=\mu$
$\frac{P_{A} V_{A}}{R T}+\frac{P_{B} V_{B}}{R T}$
$=\frac{P\left(V_{A}+V_{B}\right)}{R T}$
$P=\frac{P_{A} V_{A}+P_{B} V_{B}}{V_{A}+V_{B}}$
$=\frac{1.4 \times 0.1+0.7 \times 0.15}{0.1+0.15}$
$P=0.98\, MPa$