Question 18M.1.HL.TZ2.9

Q and R are two rigid containers of volume 3V and V respectively containing molecules of the same ideal gas initially at the same temperature. The gas pressures in Q and R are p and 3p respectively. The containers are connected through a valve of negligible volume that is initially closed.

The valve is opened in such a way that the temperature of the gases does not change. What is the change of pressure in Q?

A.     +p

B.     $\frac{+p}{2}$

C.     $\frac{-p}{2}$

D.     –p