The volume of air in a balloon is 4.5 liters when inflated. External pressure decreases the volume to 1.1 liters. If the original pressure was 1.00 atmosphere, what pressure would be required to produce that change if everything else is constant?

4.1 atm right?
4.5Lx1.00atm=1.1LxPf

2 answers

equation looks good ... Boyle's Law
constant temp
P1V1=P2V2
P2=P1*V1/V2=1atm*4.5/1.1= 4atm