Question

A sample of a gas in a piston/cyclinder apparatus occupies 41.8 mL at 1.37 atm and 21.5°C. If the volume of the sample is increased to 66.9 mL and the temperature changes to 44.6°C, what is the new pressure, in atm, of the sample? Enter your answer with three decimal places and no units.

Answer 1

Answer : The new pressure of sample in atm is, 0.923

Explanation :

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

`(P_1V_1)/(T_1)=(P_2V_2)/(T_2)`

where,

`P_1` = initial pressure of gas = 1.37 atm

`P_2` = final pressure of gas = ?

`V_1` = initial volume of gas = 41.8 mL

`V_2` = final volume of gas = 66.9 mL

`T_1` = initial temperature of gas =
`21.5^oC=273+21.5=294.5K`

`T_2` = final temperature of gas =
`44.6^oC=273+44.6=317.6K`

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

`(1.37atm* 41.8mL)/(294.5K)=(P_2* 66.9mL)/(317.6K)`

`P_2=0.923atm`

Therefore, the new pressure of sample in atm is, 0.923