CHEM 1001/CHM 1020/ Chm1025C/CHM1032C Name:__Answers
Module 6 SamplePretest
Module
Six Part E Gas Law Problems 35 points
Boyle’s
Law
1. A sample of a gas has a volume of 100 mL when measured at 25 oC
and
760 mmHg. What volume will the gas occupy at 25 oC and 380 mmHg?
V1P1=V2P2
100 mL X 760 mmHg =
200 mL (answer)
1 380 mmHg
Charles
Law
2. The volume of a
gas is 100.0 mL at 27 oC. At what temperature in degrees Celsius would the
volume of the gas be 200.0 mL, assuming the pressure
remains constant.
V1 = V2 V2
T1__ = T2
T1 T2 V1
200.0 mL x 300 K = 600 K (answer)
100.0 mL
Dalton’s
Law of Partial Pressures
3. The volume of
hydrogen collected over water is 100 mL at 25 oC and 763.8 torre. Calculate the dry volume in milliliters of
200 mL of hydrogen gas collected over water at 25 oC at 760 torre
pressure with the temperature remaining constant. (The partial pressure of water vapor at 25 oC is 23.8 torre.)
Ptotal = PH2
dry + PH2O PH2 dry = 760 torre – 23.8 torre =
736.2 torre
V1P1=V2P2
200 mL
x 736.2 torre =
193.7 mL (Answer)
760 torre
Gay-Lussac’s Law
4. A sample of gas occupies 100.0 L at 710.0 torre and 27 oC. Calculate the pressure in torre
if the temperature is changed to 127 oC , while the volume remains constant.
P1 = P2 P1 T2__ = P2
T1 T2 T1
710.0 torre x 400
K
= 946.7 torre
(answer)
300 K
Avogadro’s Law
5. A 1.5 mole sample of a gas occupies 25.0 L
at 758 torre and 27oC. Calculate the
Volume of the gas, if more molecules are injected into the vessel increasing
the moles to 2.5 moles, provided the pressure and the temperature do not
change.
V1 = V2 V1 n2__ = V2
n1 n2 n1
25.0 L x 2.5 mol = 41.7 L (answer)
1.5
mol
Ideal Gas
Equation-Combined Gas Laws
6. Calculate the
number of moles of nitrogen gas in a 5.00 L cylinder at 27 oC
and 4 atm pressure. R = 0.0821 L atm/
K mole )
PV = nRT
4 atm x 5.00
L =
0.813 mol
300 K x 0.08205 L atm/Kmol
How much does this volume
of gas weigh?
.813 mol x 28.0 g/mol = 22.8 g
(answer)
Corwin 7th Paper and
Pencil Homework:
Boyles Law: Questions 15-20 p 307-8
Charles Law: Questions 21-26 p 308
Gay-Lussac’s Law Questions27-32 p308
Combined Gas Law: Questions 33-42 p 308
Dalton’s Law: Questions 47-54 p 308
Ideal Gas Behavior and Gas
Law: Questions 55-66 p 308-9