Boyles law
P=pressure V=volume
Pressure is measured in kPa /Atm /mmHg and Volume is measured in liters
The formula for Boyles law is (P1xV1=P2 x P2)
Balloon contains 30.0 L of helium of 103.0 kPa. The balloon rises, what's the new volume now that the
pressure is 25.0 kPa?
P1=103kPa
V1=30.L
P2=25.0kPa
V2=? Liters
Note that when P increases then V decreases, when P decreases then V increases
To solve for V2, isolate V2 use formula P1 xV1 = P2 x V2
P1 xV1 = P2 xV2
P2
P2
Divide both sides of the equation by P2
P1 xV1 = P2 xV2
P2
P2
Cancel P2 on the right side of equation
Rewrite the equation to look like
P1 xV1 = V2
P2
Now plug in the numbers from above 103.0 kPa X 30.0L = 123.6 Liters
25.0 kPa
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Charles Law
T= temperature in Kelvin , V= Volume in liters
Formula V1/T1 =V2/T2
Celsius must be converted to Kelvin temperature by adding 273 to the Celsius temperature
To solve for unknown V2 Isolate V2
V1 = V2
T1 T2
When V increases so does T, When V decreases so does T.
A balloon at 24.0 •C has a volume of 4.0L. Heat the balloon to 58.0 •C, what is the new volume if
pressure remains constant?
V1=4.L.
T1=24.0 •C
T2=58.0 •C
V2 = unknown
T=kelvin= 273 + C, You must convert Celsius to Kelvin by adding 273 to the Celsius
temperature
273 + 24= 297 K
273 + 58= 331K
see next page to solve
Solve
V1 = V2 Isolate V2 the unknown by multiplying both sides of the equation byV2
T1 T2
T2 X V1 = V2 T2
T1
T2
Cancel T2 on the right side of equation
Rewrite the equation to look like
T2 xV1 = V2
T1
Now plug in the numbers from above (331.0 K) X (4.0 L) = 4.46 L
297.0 K