Question

A vessel is filled with an ideal gas at a pressure of 10 atmospheres and temp 27${}^0$C . Half of the mass of the gas is removed from the vessel & the temp. of the remaining gas is increased to 87${}^0$C . Then the pressure of the gas in the vessel will be

• A. 5 atm
• B. 6 atm
• C. 7 atm
• D. 8 atm

Answer 1

Answer: (B)

6 atm

We have Ideal gas Equation: $PV=nRT$

First the mass is halved, thus the moles of gas are halved.

$P\propto n$

So, $P_1=\frac{P_0}{2}=5atm$

Now the temperature is increased.

$P\propto T$

$\frac{P_2}{P_1}=\frac{T_2}{T_1}=\frac{360}{300}=\frac{6}{5}$

$⟹P_2=6atm$