Question

A sample of helium gas at 841 mmHg and 14.7°C is heated to 84.7°C at constant volume. Calculate its final pressure (in atm).

_________________ atm. Do NOT enter unit. Report your final answer with 3 SFs.

Answer 1

Answer: 1.38

Step-by-step explanation:

Gay-Lussac's Law: This law states that pressure is directly proportional to the temperature of the gas at constant volume and number of moles.

`P\propto T` (At constant volume and number of moles)

`(P_1)/(T_1)=(P_2)/(T_2)`

where,

`P_1` = initial pressure of gas = 841 mm Hg

`P_2` = final pressure of gas = ?

`T_1` = initial temperature of gas =
`14.7^0C=(14.7+273)K=287.7K`

`T_2` = final temperature of gas =
`84.7^0C=(84.7+273)K=357.7K`

`(841)/(287.7)=(P_2)/(357.7)`

`P_2=1045.6mm Hg=1.38atm` ( 760 mm Hg = 1atm )

Thus the final pressure is 1.38