Two gas-containers, A and B, are connected with a valve. The first container, A, has a volume of 135 mL, and the second container, B, has a volume of 117 mL. A sample of gas originally in container A is at 22.5 C and the pressure is 165 mmHg. What is the pressure (in mmHg) of the gas sample when the valve is opened and the gas now occupies both containers at a temperature of 12.7 C

85.5 mmHg is the pressure of the gas sample when the valve is opened.

Explanation:

The combined gas equation is,

where,

= initial pressure of gas in container A = 165 mmHg

= final pressure of gas = ?

= initial volume of gas in container A=

= final volume of gas = 135 mL + 117 mL = 252 mL

= initial temperature of gas in container A =

= final temperature of gas =

Now put all the given values in the above equation, we get:

85.5 mmHg is the pressure of the gas sample when the valve is opened.