Transcript 252_avagodro

GAS DENSITY AND AVAGODRO’S LAW
ONE MOLE OF ANY GAS OCCUPIES A
VOLUME OF 22.4 LITERS AT STP.
VOLUME = MOLES X 22.4L
1.
2.
3.
AT STP
GAS PRESSURE IS A COLLIGATIVE PROPERTY AT STP.
COLLIGATIVE: THE PRESSURE IS DEPENDANT ON THE NUMBER OF
MOLES OF GAS, INDEPENDENT OF THE SPECIES OF GAS AT STP.
IF YOU KNOW THE STP DENSITY OF A GAS, YOU CAN RATIO TO
MASS/22.4L TO GET MOLAR MASS.
1. EXAMPLE THE DENSITY OF A GAS IS 2g/1L, WHAT IS THE
MOLAR MASS AT STP.
2 GRAMS
1L
=
MOLAR MASS , MOLAR MASS =22.4 X 2 = 44.8 G/MOL
22.4L
GAS LAWS – U DO IT NOW
DECEMBER 15 2006 LESSON
What would be the volume of 4 moles of H2 OR A SAMPLE 4 moles of N2 AT STP
VOLUME = MOLES X 22.4L
AT STP
 VOLUME = 4 X 22.4L
AT STP
VOLUME = 89.6 L AT STP
BOTH GASES ARE 89.6L, VOLUME
IS A COLLIGATIVE PROPERTY.
HOW MANY MOLES ARE IN 44.8L OF O2 ?
VOLUME = MOLES X 22.4L
AT STP
 44.8 = MOLES X 22.4L
MOLES = 44.8/22.4
MOLES = 2
AT STP
AT STP
GAS LAWS – U DO IT NOW
DECEMBER 15 2006 LESSON
• CALCULATE THE MOLAR MASS OF A GAS WITH A DENSITY OF 0.1g/mL
, what is the molar mass AT STP.
MASS
= MOLAR MASS
22.4L
• VOLUME(L)
0.1 g
= MOLAR MASS
22.4L
 0.001L
MOLAR
 MASS
2240g/
MOL
TO CONVERT FROM Ml to L DIVIDE
#mL/1000. HERE, IT IS:
VOLUME IN THE DENSITY MUST BE IN
LITERS BECAUSE THE VOLUME IN
1 mL = 0.001 L
1000L
AVAGODRO’S LAW IS 22.4
L