Question

a sample occupies 68.0 mL at 40.0 C and 95.0 kPa. what pressure will it have if cooled to -20.0 C while the volume remains constant?

Answer 1

76.703 kPa is the pressure if a sample occupies 68.0 mL at 40.0 C and 95.0 kPa and cooled to -20 degrees while volume remains constant.

Step-by-step explanation:

Volume of the gas V1 = 68 ml

Temperature of the gas T1=40 degrees or 313.15 K

Pressure of the gas P1 = 95 Kpa OR 0.937 atm

Final temperature of the gas T2 = -20 Degrees OR 253.15 K

volume = 68 ml

Pressure P2 = ?

FROM THE FORMULA OF GAS LAW:

`(P1V1)/(T1)` =
`(P2V2)/(T2)`

volume is constant so, omitting volume values of temperature and pressure is put in the equation:

`(0.937)/(313.15)`=
`(P2)/(253.15)`

P2 =
`(253.15 X 0.937)/(313.15)`

P2 = 0.757 atm or 76.703 kPa is the pressure of the gas when cooled at -20 degrees.