Question

Two glass bulbs ${}^{\prime }{K}^{\prime }$ and ${}^{\prime }{L}^{\prime }$ are connected by a very small tube having a stop-cork. Bulb ${}^{\prime }{K}^{\prime }$ has a volume of $100c{m}^3$ and contained the gas while bulb ${}^{\prime }{L}^{\prime }$ was empty. On opening the stop-cork, the pressure fell down to $40$%. The volume of the bulb ${}^{\prime }{L}^{\prime }$ must be:

• A. $74c{m}^3$
• B. $125c{m}^3$
• C. $150c{m}^3$
• D. $250c{m}^3$

Answer 1

The correct option is C $150c{m}^3$

Let volume of vessel to be $V_L$

Pressure of $K$ vessel $\to P_1$

$V_K=100c{m}^3$

$P_1=P$ after opening of cork $P_2=P\times \frac{40}{100}\to P_2=2P/5$

$n_{K\left(i\right)}=(n_K+n_L)$

$\Rightarrow P_1{V}_K=P_2(V_L+V_K)$

$P\left(100\right)=\frac{2P}{5}(V_L+100)$

$500=2V_L+200$

$V_L=150c{m}^3$