Question 1

Which one of these samples contains the smallest number of molecules?

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Question 2

Which of the following samples of an ideal gas has the lowest density?

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Question 3

Calcium carbonate (100.1 g/mol) decomposes according to the following reaction equation: CaCO₃(s) $\rightarrow$ CaO(s) + CO₂(g) What pressure of CO₂ gas will form in a 25.0 mL jar containing 5.00 g CaCO₃ at 300 K if 0.00500% of the solid decomposes?

Accepted Answer

The answer of Calcium carbonate (100.1 g/mol) decomposes according to...

Question 4

Which of the gases shown here will exert the lowest pressure, assuming that each container has the same volume and temperature?

Accepted Answer

According to the ideal gas law, the pressure of a gas is directly proportional to its number of particles (measured in moles). From the given images, we can see that all the containers have the same volume and temperature, but different numbers of particles. Gas B has the fewest number of particles (moles) compared to the other gases, so it will exert the lowest pressure. Therefore, option B is the correct answer.

Question 5

The density of a pure gas at STP depends on its __________

Accepted Answer

The density of a gas at STP (standard temperature and pressure) is determined by its molar mass. This is because at STP, the volume and temperature are constant, while the pressure is fixed at 1 atm. Therefore, the only variable factor in the ideal gas law equation (PV = nRT) is the number of moles (n), which is directly proportional to the molar mass of the gas.

Question 6

A 1.50 mol sample of He occupies a volume of 2.50 L at a pressure of 14.7 atm. What will be the pressure of a 1.50 mol sample of H₂ gas under the same conditions?

Accepted Answer

The pressure of a gas is independent of its chemical identity and depends only on its volume, temperature, and amount (moles) according to the ideal gas law. Since the conditions and the amount of gas are the same, the pressure will also be the same, regardless of the gas type.

Question 7

In an experiment, 7.5 mol of a gas are held in a 3.5 L container at 39°C. What pressure does the gas exert if it is assumed to be ideal?

Accepted Answer

The answer of In an experiment, 7.5 mol of a...

Question 8

What is the pressure of a 3.5 mmol sample of ethane (C₂H₆) gas contained in a 0.500 L flask at 298 K?

Accepted Answer

We can use the Ideal Gas Law to solve for pressure:

PV = nRT

where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature.

First, we convert the given amount of ethane from moles to units of n (number of particles) by multiplying by Avogadro's number:

3.5 mmol * (6.022 x 10^23 particles/mol) = 2.1097 x 10^22 particles

Next, we convert the given volume from L to mL (milliliters) so that we have the correct units for pressure:

0.500 L * (1000 mL/L) = 500 mL

Now we can plug in our known values and solve for P:

P = (nRT)/V

P = [(2.1097 x 10^22 particles) x (0.0821 L-atm/mol-K) x (298 K)] / (500 mL)

P = 130 mm Hg

Therefore, the answer is C, 130 mm Hg.

Question 9

Which of the following reactions will result in a reduced total pressure?

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Question 10

What is the temperature if 5.0 g of methane (CH₄) in a 100.0 mL container exerts a pressure of 42 atm?

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Question 11

What volume is occupied by 1.00 mol of an ideal gas at 1.00 atm and 0.00°C?

Accepted Answer

At standard temperature and pressure (STP), which is defined as 1.00 atm and 0.00°C, 1.00 mol of an ideal gas occupies a volume of 22.4 L (as determined by Avogadro's Law). Therefore, the correct answer is choice A.

Question 12

An unknown gas held in a 25.0 mL flask at 45°F exerts a pressure of 25 mtorr. By using this information with the ideal gas law, it is possible to determine __________

Accepted Answer

The ideal gas law can be used to calculate the number of moles (and thus molecules) of the gas in the container, given the pressure, volume, and temperature.

Question 13

How many moles of propane are contained in a 5.00 L tank at 450 torr and 25°C?

Accepted Answer

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Question 14

The pressure gauge on a cylinder used to fill balloons with He shows a pressure of 1275 psi at a temperature of 25°C. Assuming the cylinder has a volume of 10 L, how many grams of He does the cylinder contain?

Accepted Answer

We can use the ideal gas law equation, PV = nRT, to solve for the number of moles of He in the cylinder, and then convert to grams using the molar mass of He.

First, we need to convert the pressure to units of atm, since R (the gas constant) has units of L•atm•K⁻¹.

1 atm = 14.7 psi, so the pressure in the cylinder is 1,275 psi ÷ 14.7 psi/atm = 86.7 atm.

Next, we convert the temperature to units of Kelvin:

T = 25°C + 273.15 = 298.15 K

Now we can plug in the values and solve for n:

(86.7 atm)(10 L) = n(0.08206 L•atm•K⁻¹)(298.15 K)

n = 3.58 moles He

Finally, we convert to grams using the molar mass of He:

(3.58 mol He)(4.00 g He/mol) = 14.3 g He, which rounds to 142 g.

Therefore, the cylinder contains 142 grams of He, which is answer choice B.

Question 15

Indicate the gas with the greatest density at STP.

Accepted Answer

Density is directly proportional to molar mass. Among the given options, Ar has the highest molar mass and therefore the greatest density at STP.

Question 16

In an experiment, 25.0 mL of a gas with a pressure of 1.00 atm is contained in a balloon at 25.0°C. The balloon is then cooled to 5.0°C, and the pressure is found to be 0.750 atm. What is the volume of the gas under the new conditions?

Accepted Answer

The answer of In an experiment, 25.0 mL of a...

Question 17

What volume is occupied by 1.00 mol of an ideal gas at 1.00 bar and 0.00°C?

Accepted Answer

The answer of What volume is occupied by 1.00 mol...

Question 18

Which of the following is unimportant when using the ideal gas law?

Accepted Answer

The ideal gas law (PV=nRT) is based on the assumption that gases behave ideally, which means they follow certain rules regardless of their chemical identity. Therefore, the chemical identity of the gas sample is not important when using the ideal gas law.

Question 19

Which of the gas samples shown below in identical containers has the lowest density (g/L)?

Accepted Answer

The ideal gas law states that density is inversely proportional to molar mass at constant pressure and temperature. Since all of the gases are in identical containers with the same pressure and temperature, the gas with the lowest molar mass will have the lowest density. Looking at the periodic table, we can see that hydrogen (H2) has the lowest molar mass out of all the choices given. Therefore, choice A, which contains H2, has the lowest density.

Question 20

Four containers, each with the same volume and at the same temperature, are shown in the following diagrams. Which container is at the highest pressure?

Accepted Answer

According to the ideal gas law, pressure is directly proportional to the number of molecules in a given volume and at a constant temperature. Container D has the highest pressure because it has the most number of molecules of gas due to its higher density (molecules are packed more closely together).

Quiz 6: Properties of Gases: the Air We Breathe

Which one of these samples contains the smallest number of molecules?

Which of the following samples of an ideal gas has the lowest density?

Calcium carbonate (100.1 g/mol) decomposes according to the following reaction equation: CaCO₃(s) $\rightarrow$ CaO(s) + CO₂(g) What pressure of CO₂ gas will form in a 25.0 mL jar containing 5.00 g CaCO₃ at 300 K if 0.00500% of the solid decomposes?

Which of the gases shown here will exert the lowest pressure, assuming that each container has the same volume and temperature?

The density of a pure gas at STP depends on its __________

A 1.50 mol sample of He occupies a volume of 2.50 L at a pressure of 14.7 atm. What will be the pressure of a 1.50 mol sample of H₂ gas under the same conditions?

In an experiment, 7.5 mol of a gas are held in a 3.5 L container at 39°C. What pressure does the gas exert if it is assumed to be ideal?

What is the pressure of a 3.5 mmol sample of ethane (C₂H₆) gas contained in a 0.500 L flask at 298 K?

Which of the following reactions will result in a reduced total pressure?

What is the temperature if 5.0 g of methane (CH₄) in a 100.0 mL container exerts a pressure of 42 atm?

What volume is occupied by 1.00 mol of an ideal gas at 1.00 atm and 0.00°C?

An unknown gas held in a 25.0 mL flask at 45°F exerts a pressure of 25 mtorr. By using this information with the ideal gas law, it is possible to determine __________

How many moles of propane are contained in a 5.00 L tank at 450 torr and 25°C?

The pressure gauge on a cylinder used to fill balloons with He shows a pressure of 1275 psi at a temperature of 25°C. Assuming the cylinder has a volume of 10 L, how many grams of He does the cylinder contain?

Indicate the gas with the greatest density at STP.

In an experiment, 25.0 mL of a gas with a pressure of 1.00 atm is contained in a balloon at 25.0°C. The balloon is then cooled to 5.0°C, and the pressure is found to be 0.750 atm. What is the volume of the gas under the new conditions?

What volume is occupied by 1.00 mol of an ideal gas at 1.00 bar and 0.00°C?

Which of the following is unimportant when using the ideal gas law?

Which of the gas samples shown below in identical containers has the lowest density (g/L) ?

Four containers, each with the same volume and at the same temperature, are shown in the following diagrams. Which container is at the highest pressure?

Quiz 6: Properties of Gases: the Air We Breathe

Which one of these samples contains the smallest number of molecules?

Which of the following samples of an ideal gas has the lowest density?

Calcium carbonate (100.1 g/mol) decomposes according to the following reaction equation: CaCO3(s) →\rightarrow→ CaO(s) + CO2(g) What pressure of CO2 gas will form in a 25.0 mL jar containing 5.00 g CaCO3 at 300 K if 0.00500% of the solid decomposes?

Which of the gases shown here will exert the lowest pressure, assuming that each container has the same volume and temperature?

The density of a pure gas at STP depends on its __________

A 1.50 mol sample of He occupies a volume of 2.50 L at a pressure of 14.7 atm. What will be the pressure of a 1.50 mol sample of H2 gas under the same conditions?

In an experiment, 7.5 mol of a gas are held in a 3.5 L container at 39°C. What pressure does the gas exert if it is assumed to be ideal?

What is the pressure of a 3.5 mmol sample of ethane (C2H6) gas contained in a 0.500 L flask at 298 K?

Which of the following reactions will result in a reduced total pressure?

What is the temperature if 5.0 g of methane (CH4) in a 100.0 mL container exerts a pressure of 42 atm?

What volume is occupied by 1.00 mol of an ideal gas at 1.00 atm and 0.00°C?

An unknown gas held in a 25.0 mL flask at 45°F exerts a pressure of 25 mtorr. By using this information with the ideal gas law, it is possible to determine __________

How many moles of propane are contained in a 5.00 L tank at 450 torr and 25°C?

The pressure gauge on a cylinder used to fill balloons with He shows a pressure of 1275 psi at a temperature of 25°C. Assuming the cylinder has a volume of 10 L, how many grams of He does the cylinder contain?

Indicate the gas with the greatest density at STP.

In an experiment, 25.0 mL of a gas with a pressure of 1.00 atm is contained in a balloon at 25.0°C. The balloon is then cooled to 5.0°C, and the pressure is found to be 0.750 atm. What is the volume of the gas under the new conditions?

What volume is occupied by 1.00 mol of an ideal gas at 1.00 bar and 0.00°C?

Which of the following is unimportant when using the ideal gas law?

Which of the gas samples shown below in identical containers has the lowest density (g/L) ?

Four containers, each with the same volume and at the same temperature, are shown in the following diagrams. Which container is at the highest pressure?

Calcium carbonate (100.1 g/mol) decomposes according to the following reaction equation: CaCO₃(s) $\rightarrow$ CaO(s) + CO₂(g) What pressure of CO₂ gas will form in a 25.0 mL jar containing 5.00 g CaCO₃ at 300 K if 0.00500% of the solid decomposes?

A 1.50 mol sample of He occupies a volume of 2.50 L at a pressure of 14.7 atm. What will be the pressure of a 1.50 mol sample of H₂ gas under the same conditions?

What is the pressure of a 3.5 mmol sample of ethane (C₂H₆) gas contained in a 0.500 L flask at 298 K?

What is the temperature if 5.0 g of methane (CH₄) in a 100.0 mL container exerts a pressure of 42 atm?