Question

a sample of helium occupies a volume of 101.2 mL at a pressure of 790 mmHg. at what pressure would the volume be 120 mL?

Answer 1

Answer : The final pressure will be, 666.2 mmHg

Explanation :

Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

`P\propto (1)/(V)`

or,

`P_1V_1=P_2V_2`

where,

`P_1` = initial pressure = 790 mmHg

`P_2` = final pressure = ?

`V_1` = initial volume = 101.2 mL

`V_2` = final volume = 120 mL

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

`790mmHg* 101.2mL=P_2* 120mL`

`P_2=666.2mmHg`

Therefore, the final pressure will be, 666.2 mmHg