MGCCC, Perk Learning Lab

Created by Tara L. Moore

GAS LAWS

Boyle’s Law: P1V1=P2V2, Temperature is constant

P1 = P2V2 V1 = P2V2 P2 = P1V1 V2 = P1V1

V1 P1 V2 P2

Charles’s Law: V1 = V2, Pressure is constant, Temperature must be in Kelvin T1 T2

V1 = V2T1 T1 = V1T2 V2 = V1T2 T2 = V2T1

T2 V2 T1 V1

Gay-Lussac’s Law: P1 = P2, Volume is constant, Temperature must be in Kelvin T1 T2

P1= P2T1 T1 = P1T2 P2 = P1T2 T2 = P2T1

T2 P2 T1 P1

Combined Gas Law: P1V1 = P2V2, Temperature must be in Kelvin

T1 T2

P1=P2V2T1 V1=P2V2T1 T1=P1V1T2 P2=P1V1T2 V2=P1V1T2 T2=P2V2T1

T2V1 T2P1 P2V2 T1V2 T1P2 P1V1

Dalton’s Law of Partial Pressures

PT = P1 + P2 + P3 + …….

Patm = Pgas + PH2O

One of the very most important things to remember when plugging values into these equations is that the units must coincide. For example, if you are given one pressure value in atm and one pressure value in mm Hg, before you can plug these values into an equation, you must convert one of them so the unit values match. The matching units will allow you to cancel. This applies to pressure, volume and temperature.

CONVERSION FORMULAS

°F= 1.8°C + 32° °C= (°F - 32°) (remember 5/9 =1.8)

K = °C + 273° 1.8

1 atm = 760 torr= 760 mm Hg = 101,325 Pascals=101.325 kilo-Pascals

Ideal Gas Law: PV= nRT STP= Standard Temperature and Pressure

P= pressure in atm Standard Temperature = 273 K

V= volume in L Standard Pressure = 1 atm

n= number of moles 1 mole of any gas at STP occupies 22.4L

T= temperature in K

R= constant = 0.0821 (L*atm)/(mole*K)

P=nRT V=nRT n=PV R=PV T=PV

V P RT nT nR

n= m where m= mass in grams, MW= molecular weight g/mol: PV = mRT

MW MW

m=PVMW MW=mRT D=MWP

RT PV RT

MW=DRT

Density = g/L