CHEM 1045 QUIZ CHAPTER 5
Exercise 5.54: Problems by Topic  Ideal Gas Law
Part A
Use the molar volume of a gas at STP to calculate the density (in g/L) of carbon dioxide gas at STP.
ANSWER:



Correct
Exercise 5.37: Problems by Topic  Simple Gas Laws
A 48.2mL sample of gas in a cylinder is warmed from 22 ∘C to 85 ∘C.
Part A
What is its volume at the final temperature? (Assume constant pressure.)
ANSWER:



Correct
Exercise 5.43: Problems by Topic  Ideal Gas Law
A cylinder contains 30.5 L of oxygen gas at a pressure of 2.0 atm and a temperature of 310 K .
Part A
How much gas (in moles) is in the cylinder?
Express your answer using two significant figures.
ANSWER:



Correct
Exercise 5.46: Problems by Topic  Ideal Gas Law
A weather balloon is inflated to a volume of 29.9 L at a pressure of 733 mmHg and a temperature of 31.5 ∘C. The balloon rises in the atmosphere to an altitude, where the pressure is 375 mmHg and the temperature is 15.3 ∘C.
Part A
Assuming the balloon can freely expand, calculate the volume of the balloon at this altitude.
ANSWER:
Exercise 5.53: Problems by Topic  Ideal Gas Law
Part A
Use the molar volume of a gas at STP to determine the volume (in L) occupied by 14.0 g of neon at STP.
Exercise 5.57: Problems by Topic  Molar Volume, Density, and Molar Mass of a Gas
An experiment shows that a 247 −mL gas sample has a mass of 0.436 g at a pressure of 748 mmHg and a temperature of 26 ∘C.
Part A
What is the molar mass of the gas?
ANSWER:
Exercise 5.62: Problems by Topic  Partial Pressure
A gas mixture with a total pressure of 770 mmHg contains each of the following gases at the indicated partial pressures: CO2, 253 mmHg ; Ar, 114 mmHg ; and O2, 165 mmHg . The mixture also contains helium gas.
Part A
What is the partial pressure of the helium gas?
Part B
What mass of helium gas is present in a 13.1L sample of this mixture at 279 K ?
ANSWER:
Exercise 5.65: Problems by Topic  Partial Pressure
A gas mixture contains 1.17 gN2 and 0.88 gO2 in a 1.45L container at 20 ∘C.
Part A
Calculate the mole fraction of N2.
Express your answer using two significant figures.
Correct
Part B
Calculate the mole fraction of O2.
Express your answer using two significant figures.
ANSWER:
Part C
Calculate the partial pressure of N2.
Express your answer using two significant figures.
ANSWER:
Part D
Calculate the partial pressure of O2.
Express your answer using two significant figures.
ANSWER:
Exercise 5.67: Problems by Topic  Partial Pressure
The hydrogen gas formed in a chemical reaction is collected over water at 30.0 ∘C at a total pressure of 730 mmHg .
Part A
What is the partial pressure of the hydrogen gas collected in this way?
ANSWER:
Part B
If the total volume of gas collected is 720 mL , what mass of hydrogen gas is collected?
ANSWER:
Exercise 5.77: Problems by Topic  Reaction Stiochiometry Involving Gases
Hydrogen gas (a potential future fuel) can be formed by the reaction of methane with water according to the following equation:
CH4(g)+H2O(g)→CO(g)+3H2(g)
In a particular reaction, 26.5 L of methane gas (measured at a pressure of 736 torr and a temperature of 25 ∘C) is mixed with 22.2 L of water vapor (measured at a pressure of 704 torr and a temperature of 125 ∘C). The reaction produces 26.8 L of hydrogen gas measured at STP.
Part A
What is the percent yield of the reaction?
ANSWER:


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