Academic Subjects
➤
Chemistry
➤
General Chemistry
➤
Gases
➤
Calculating Volume To Pressure Ratio Of Gas
A sample of gas occupies a volume of
3.2 L
at
1.8 atm
.
What would be its volume if the pressure is doubled? reduced by one-half?
Applying the Ideal Gas Law, we conclude that temperature is kept constant
and there is no mention of moles, i.e. we do not need T, n and R
p
V
=
nRT
,
also called
Boyle's Law
since this is the same gas under different conditions,
let's set up a ratio between the initial and the final stage
(
p
initial
)(
V
initial
) = (
p
final
)(
V
final
)
Volume
when pressure is doubled
(1.8
atm
)(3.2
L
) = (3.6
atm
) (
L
)
(1.8
atm
)(3.2
L
)
/
(3.6
atm
)
= 1.6
L
Ideal Gas Law Revamped
pressure reduced by 1/2
(1.8
atm
)(3.2
L
) = (0.9
atm
) (
L
)
(1.8
atm
)(3.2
L
)
/
(0.9
atm
)
= 6.4
L
Temperature
When the pressure of this gas is doubled,
the final volume is 1.6 L,
whereas,
when the pressure of this gas is reduced by 1/2,
the final volume is 6.4 L
perfectly demonstrating Boyle's Law, i.e.
the relationship between pressure and volume
when one goes up, the other one goes down