Posted by lt on .
Fill a balloon with helium gas to a volume of 2.68 L at 23 celsius and 789mmHg. What would the volume of helium if the pressure changes to 632 mmHg but the temperature is unchanged.
This is how I solved it
V2 = V1 X P1/P2
2.68L X 23/789 = V2 =.078 L
Is this correct

Chemistry 
DrBob222,
(P1V1)/T1 = (P2V2)/T2
Since T1 = T2 you can omit that from the equation. 
Chemistry 
DrBob222,
Sorry I didn't see your answer. The equation you used is ok but you didn't substitute the correct numbers.
V1 = 2.68 as you have.
P1 = 789 mm
P2 = 632 mm
The 23 you used is the temperature and doesn't enter the equation.