The Gas Laws. Jeopardy Categories Boyle’s Law Charles’ Law Combined Gas Law PV=nRTGraham’s Law...
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Transcript of The Gas Laws. Jeopardy Categories Boyle’s Law Charles’ Law Combined Gas Law PV=nRTGraham’s Law...
Jeopardy CategoriesBoyle’s
Law
Charles’ Law
Combined Gas Law
PV=nRT Graham’s Law
Dalton’s Law
100
500500 500500 500
100 100 100 100
1000 1000 1000 100010001000
200
300
200
300
200
300
200
500
200 200
100
300 300 300
Boyle’s Law- $100
According to Boyle’s Law, the volume of a gas varies ____________ (directly or inversely)
with its pressure, assuming that temperature is constant.
BACK
INVERSELY
Boyle’s Law- $200
According to Boyle’s Law, the volume of a gas ______________ (increases, decreases, or stays the same)
when the pressure increases and temperature is held constant.
BACK
DECREASES
Boyle’s Law- $300A sample of oxygen gas at constant temperature occupies a volume of 250. mL at 740. torr pressure. What volume in mL will it occupy at 800. torr pressure?
BACK
mLV
VtorrmLtorr
231
))(800().250)(.740(
2
2
mLV
VHgmmmLHgmm
426
))(.760().450)(.720(
Hg mm 760 atm 1 Pressure Standard
2
2
Boyle’s Law- $500
Ammonia gas occupies a volume of 450. mL at a pressure of 720. mm Hg. What volume in mL will it occupy at standard pressure?
BACK
Boyle’s Law- $1000
Fluorine gas has a volume of 317 mL. When the volume is decreased to 250. mL, its pressure is 1.50 atm. What was the original pressure in torr?
BACKtorrP
mLtorrmLP
899
).250)(1140()317)((
1140torr 1.5atm
torr760 atm 1
1
1
CHARLES $100
According to Charles’ Law, the volume of a gas varies ____________ (directly or inversely)
with the Kelvin temperature, assuming that pressure is constant.
BACK
DIRECTLY
CHARLES - $200
According to Charles’ Law, the volume of a gas ______________ (increases, decreases, or stays the same)
when the temperature increases and pressure is held constant.
BACK
INCREASES
CHARLES - $300
A sample of nitrogen occupies a volume of 0.250 L at 298 K. What volume in liters will it occupy at 368 K?
BACK
LVK
V
K
L
309.0368298
250.0
2
2
CHARLES - $500
Hydrogen gas was cooled from 423K to 323K. Its new volume is 0.075 liters. What was its original volume?
BACK
LVK
L
K
V
098.0323
075.0
423
1
1
CHARLES - $1000
A sample of argon gas is cooled and its volume decreased from 0.380 mL to 0.250 mL. If its final temperature was 218 K, what was its original temperature in degrees Celsius?
BACKCT
KT
K
L
T
L
4.58
4.331
218
250.0380.0
1
1
1
Combined - $100
What are the three variables in the Combined Gas Law?
BACK
VOLUMEPRESSURE
TEMPERATURE
Combined - $200P1 = 1.5 atm P2 = 2.5 atm
V1 = 3.0 L V2 = ?
T1 = 293 K T2 = 303 K
BACK
LVK
Vatm
K
Latm
9.1303
))(5.2(
293
)0.3)(5.1(
2
2
Combined - $300P1 = 720. torr P2 = ?
V1 = 0.256 L V2 = 0.250 L
T1 = 298 K T2 = 323 K
BACK
torrPK
LP
K
Ltorr
799323
)250.0)((
298
)256.0)(720(
2
2
Combined - $500P1 = 95.0 kPa P2 = 101kPa
V1 = 4.00 L V2 = 6.00 L
T1 = ? T2 = 471 K
BACK
KT
K
LkPa
T
LkPa
295
471
)00.6)(101()00.4)(0.95(
1
1
Combined - $1000
A gas has an initial volume of 125 mL and pressure of 125 kPa. When its volume is decreased to 100. mL and its pressure is decreased to 100. kPa, its temperature is changed to 348 K. What is the initial temperature of this gas in K?
BACKKT
K
mLkPa
T
mLkPa
544
348
)100)(.100()125)(125(
1
1
PV=nRT - $100
Why must pressure be in atmospheres, volume be in liters, and temperature be in Kelvin when using the constant with a numerical value of 0.0821?
BACK
Because the Universal Gas Constant, R, that has a value of 0.0821 has a unit of (L•atm)/(mol•K). The units must be consistent or they will not cancel out.
PV=nRT - $200
How many moles of oxygen will occupy a volume of 2.5 liters at 1.2 atm and 298 K?
BACK
moln
KKmol
atmLnLatm
12.0
)298)(0821.0()5.2)(2.1(
PV=nRT - $300
What volume will 2.0 moles of nitrogen occupy at 0.947 atm and 293 K?
BACK
LV
KKmol
atmLmolVatm
51
)293)(0821.0)(0.2())(947.0(
PV=nRT - $500
At what temperature will 0.70 mol of chlorine gas exert a pressure of 900. torr of pressure at a and a volume of 500. mL?
BACK
KT
TKmol
atmLmolLatm
.10
))(0821.0)(70.0()5.0)(184.1(
PV=nRT - $1000
An elemental gas has a mass of 10.3 g. If the volume is 58,400 mL and the pressure is 758 mm Hg at a temperature of 2.5°C, how many moles are present? What is the gas?
BACKHELIUM is gas the
/0.4574.2
3.10
57.2
)5.275)(0821.0)(()4.58)(997.0(
molgmol
gMM
moln
KKmol
atmLnLatm
GRAHAM - $100
Graham’s Law allows a scientist to make predictions about what property of gases if the molecular masses are known?
BACK
Rates of EFFUSION
GRAHAM - $200
According to Graham’s Law, a gas will effuse at a rate that is _____________ proportional to the square root of its molecular mass.
BACK
INVERSELY
GRAHAM - $300
Based on molecular masses, which will effuse faster: Hydrogen or Oxygen
BACK
faster effuse illHydrogen w
/0.32
/0.2
2
2
molgOMM
molgHMM
GRAHAM - $500
Arrange the following gases in order of increasing rates of effusion (slowest to fastest): NH3, CO2, He, Cl2
BACKHeNHCOCl
molgCl
molgHe
molgCO
molgNH
322
2
2
3
/0.71
/0.4
/0.44
/0.17
GRAHAM - $1000
Under the same conditions of temperature and pressure, what is the relative rate of effusion of oxygen gas effuse compared to hydrogen gas?
BACK25.0
/0.32
/0.2
2
2
2
2
H
O
H
O
rate
rate
molg
molg
rate
rate
DALTON - $100
Dalton’s Law says that the sum of the individual pressures of all the gases that make up a mixture is equal to the ___________ ___________.
BACK
TOTAL PRESSURE
DALTON - $200
The partial pressures of a gas are 22.1 torr, 168 torr, and 33.0 torr. What is the total pressure of this gas?
BACK
torrtorrtorrtorr 2230.331681.22
DALTON - $300
A 250. mL sample of oxygen is collected over water at 25.0°C and 760.0 torr pressure. What is the pressure of the dry gas alone? (Vapor pressure of water at 25.0 °C = 23.8 torr)
BACK
torrP
torrPtorr
O
O
736
8.230.760
2
2
DALTON - $500
A mixture of 2.00 moles of hydrogen, 3.00 moles of ammonia, 4.00 moles of carbon dioxide, and 5.00 moles of nitrogen exerts a total pressure of 800. torr. What is the partial pressure in torr of carbon dioxide?
BACK
torrtorrTotalmol
COmol229.800
00.14
00.4 2
DALTON - $1000
BACK
What element is used when discussing units of pressure in mm?
(pressure= mm ____ )
Mercury ; Hg
