1. The problem statement, all variables and given/known data Air is pumped into a bicycle tire. The 43 moles of air initially in the tire have a gauge pressure of 1 atm. How many moles of air must be pumped into the tire in order to raise the gauge pressure to 5 atm? Assume that the volume and temperature of the air inside the tire are approximately constant. 2. Relevant equations Ideal Gas Law: PV = nRT 3. The attempt at a solution Since the V and T were constant, as well as R, I set it up as (P1V1)/(n1T1) = (P2V2)/(n2T2) on the condition that R1 = R2. V1=V2, T1=T2 So that would leave the equation at P1/n1 = P2/n2. I decided to plug in and solve. P1=1 atm, n1=43 moles, P2=5 atm. 1/43 = 5/n2 When I solved for n2, I came out with 215 moles. My homework said it was wrong. can someone tell me where I went wrong?