11 – Gases “Sample” Test
/34 Marks
Name:
___________________________________________
Date:
___________________________________________
Instructions:
1) This is a CLOSED BOOK test.
2) This test must be completed during the scheduled class time.
3) Please submit all of your rough work with your test.
A.
Convert each of the following measurements to the indicated unit of pressure. (6 Marks)
1)
3.5 atm
= __________ mmHg
4)
825 mmHg
= __________ atm
2)
640 torr
= __________ atm
5)
2.40 atm
= __________ psi
3)
1.8 atm
= __________ Pa
6)
58.0 in Hg
= __________ atm
B.
A sample of nitrogen gas (N2) occupies a volume of 520 mL at 0.75 atm. What will be the final
pressure of the gas if the volume of this sample increases to 770 mL? Assume that temperature and
quantity remain constant. (3 Marks)
C.
A sample of carbon dioxide (CO2) occupies a volume of 820 mL at 75°C and 0.75 atm. What will be
the final volume of the gas if the temperature decreases to 35°C and the pressure increases to 1.25
atm? Assume the quantity of the gas remains constant. (5 Marks)
CHEM 1061 – ACE Chemistry
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11 – Gases “Sample” Test
/34 Marks
D.
A sample of sulphur trioxide (SO3) gas occupies a volume of 1.25 L at 21°C. What will be the new
volume of the gas if the temperature decreases to 15°C? Assume that pressure and quantity remain
constant. (5 marks)
E.
How many moles of oxygen gas (O2) would occupy a volume of 2.6 L at a pressure of 1.5 atm and a
temperature of 32°C. (4 Marks)
F.
Calculate the Kelvin temperature of 37.5 moles of argon (Ar) gas that has a volume of 725 L argon
(Ar) and a pressure of 2.50 atm. (3 Marks)
G.
A gas mixture contains hydrogen (H2), nitrogen (N2), and oxygen (O2). Calculate the total pressure of
this system given that hydrogen has a partial pressure of 810 torr, nitrogen has a partial pressure of
760 torr, and oxygen has a partial pressure of 690 torr. (3 Marks)
CHEM 1061 – ACE Chemistry
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11 – Gases “Sample” Test
H.
/34 Marks
Ammonia (NH3) reacts with oxygen (O2) to form nitrogen monoxide (NO) and water (H2O) as
represented by the following chemical equation. How many grams of water vapour can be
produced from 15 L of oxygen under STP conditions? (3 Marks)
4 NH3 (l) + 5 O2 (g)
I.
4 NO(g) + 6 H2O(g)
How many moles of water (H2O) are required to produce 8.25 L of oxygen (O2) at a
temperature of 325 K and a pressure of 0.988 atm? (2 Marks)
2 H2O (l)
CHEM 1061 – ACE Chemistry
2 H2 (g) + O2 (g)
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11 – Gases “Sample” Test
/34 Marks
Conversion Units of Pressure
Unit
Pascal (Pa)
Atmosphere (atm)
Average Air Pressure at Sea Level
101,325 Pa
1 atm
Millimeter of mercury (mmHg)
760 mm Hg
Inches of mercury (in Hg)
29.92 in Hg
Torrs (torr)
760 torr
Pounds per square inch (psi)
14.7 psi
Boyle’s Law
Charles’ Law
Combined Gas Law
Avogadro’s Law
CHEM 1061 – ACE Chemistry
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11 – Gases “Sample” Test
/34 Marks
All Formulas Rearranged
Boyle’s Law:
Charles’ Law:
Combined Gas Law:
Avogadro’s Law:
Ideal Gas Law:
Dalton’s Law of Partial Pressures:
CHEM 1061 – ACE Chemistry
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11 – Gases “Sample” Test
/34 Marks
Answers:
A1) 2,700 mmHg
A2) 0.84 atm
A3) 180,000 Pa
A4) 1.09 atm
A5) 35.3 psi
A6) 1.94 atm
B)
0.51 atm
C)
440 mL
D)
1.22 L
E)
0.16 mol
F)
589 K
G)
2,260 torr
H)
14 g
I)
0.611 mol
CHEM 1061 – ACE Chemistry
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