Charles Law V1 =V2 P constant T1 T2 Boyles Law P1V1 = P2V2 T constant Combined P1V1=P2V2 T1 T2 Gay-Lussac’s Law P1=P2 V constant T1 T2 ALL temperatures must be in Kelvin!!
Ideal Gas Equation PV=nRT P pressure V volume (L) n moles T temperature (K) R gas constant .082 L∙atm mol∙K 8.31 L∙kPa mol∙K 62.4 L∙torr mol∙K
Find Volume What volume would be occupied by 1.00 moles of gas at 0˚C and 1 atm pressure? V= nRT=(1.00 mole)(.082 L∙atm/mol∙K)(273K) P 1 atm = 22.4L
When given three of the four variables, we can find the fourth. A gas has a volume of 2.20L at 25◦C. If there are .085 moles of the gas, under what pressure must the gas be held? P = nRT V P = (.085mole)(0.0821 L∙atm)(298K) 2.20L mol∙K = .945 atm (or 95.8 kPa or 718 torr)
Find moles A gas has a volume of 31.2L at 28˚C and 82.6 kPa. How many moles are in the sample? n = PV = (82.6kPa)(31.2L) RT (8.31kPa∙L/mol∙K)(301K) = 1.03 mol How many molecules would that be? 1.03 mol x 6.02 x 1023 molecules/mol = 6.20 x 1023 molecules