Chemistry
posted by Monique on .
How many moles of gas must be forced into a 3.5 L ball to give it a gauge pressure of 9.4 psi at 25 degrees C? The gauge pressure is relative to atmospheric pressure. Assume that atmospheric pressure is 14.7 psi so that the total pressure in the ball is 24.1 psi
Ok so I'm doing PV=nRT solving for n. PV/RT
So I'm converting psi to atm but I'm confused what is all the extra info given. Isn't it 9.4 psi / 14.7 psi x 1 atm

No, if the gauge pressure is 9.4 then the pressure in the ball will be 14.7+9.4 psi = 24.1 psi and that's what the other information tells you. So
24.1 psi x (1 atm/14.7 psi) = ?atm
Then n  PV/RT 
Ahhhhh thank you!!!!! I was so frustrated

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