Posted by Anna on Wednesday, November 12, 2008 at 8:34pm.
CorrecT!
All look ok except 38 and 46.
The answer on 38 is correct; I just wondered why you changed it to atmospheres since the problem didn't ask for it. For 46 I obtained 3.658 which I would round to 3.66 mL.
I thought that you always had to use atm in the equations.
No, using atmospheres is necessary only in PV = nRT and then only when V is in Liters and R = 0.08206 (units are L*atm/mol*K). You may use P in kPa in that formula if you use R as 8.3145 J/mol*K.
When using P1V1/T1 = P2V2/T2 or one of the variations of that (P1V1 = P2V2 etc), P and V can be in ANY unit you choose as long as you keep the units consistent. That is, if P1 is in atm than P2 must be in atm. If P1 is in kPa or mm Hg, then P2 must be in kPa or mm Hg. The same holds true for volume; it need not be in liters but any unit of your choosing but you must be consistent. That is NOT true for T. T1 and T2 must be in Kelvin.
How did you get #34?