Question 1

Which statement is false

Accepted Answer

This statement is false because molecules in an ideal gas do not all have the same kinetic energy at constant temperature. While the average kinetic energy is the same, individual molecular energies can vary.

Question 2

Liquid nitrogen has a density of 0.807 g/mL at -195.8 ^$\circ$C. If 1.00 L of N₂(l) is allowed to warm to 25^$\circ$C at a pressure of 1.00 atm, what volume will the gas occupy (R = 0.08206 L*atm/K*mol)

Accepted Answer

First, we need to find the number of moles of nitrogen gas present in 1 L of liquid nitrogen:
Density = mass/volume
0.807 g/mL = mass/1 L
mass = 0.807 kg/L
Molar mass of nitrogen gas (N2) = 28.02 g/mol
Number of moles = mass/molar mass
Number of moles = 0.807 kg/L / (28.02 g/mol)
Number of moles = 0.0288 mol/L

Using the ideal gas law, we can find the final volume of the gas at 25°C and 1 atm pressure:
PV = nRT
V = nRT/P
V = (0.0288 mol/L)(0.08206 L atm/mol K)(298 K)/(1 atm)
V = 0.705 L

Therefore, the gas will occupy 0.705 L at 25°C and 1 atm pressure, which corresponds to choice C.

Question 3

9.45 g of liquid hexane (C₆H₁₄) is introduced into a 10.0 L vessel containing 13.15 atm of oxygen gas at 21ºC and ignited, yielding carbon dioxide and water. If the vessel is then cooled to -10.ºC, what will be the gas pressure inside the vessel

Accepted Answer

First, determine the moles of hexane (C6H14) using its molar mass (86.18 g/mol): $9.45 \, \text{g} \times \frac{1 \, \text{mol}}{86.18 \, \text{g}} = 0.1096 \, \text{mol}$. The combustion reaction is $2C_6H_{14} + 19O_2 \rightarrow 12CO_2 + 14H_2O$. From the stoichiometry, 0.1096 mol of hexane will consume $0.1096 \, \text{mol} \times \frac{19}{2} = 1.042 \, \text{mol}$ of $O_2$ and produce $0.1096 \, \text{mol} \times 6 = 0.6576 \, \text{mol}$ of $CO_2$ and $0.1096 \, \text{mol} \times 7 = 0.7672 \, \text{mol}$ of $H_2O$. Initially, there are $13.15 \, \text{atm} \times \frac{10.0 \, \text{L}}{0.0821 \, \text{L atm/mol K} \times 294 \, \text{K}} = 5.45 \, \text{mol}$ of $O_2$. After reaction, $5.45 \, \text{mol} - 1.042 \, \text{mol} = 4.408 \, \text{mol}$ of $O_2$ remain. Total moles of gas after reaction: $4.408 + 0.6576 + 0.7672 = 5.8328 \, \text{mol}$. Using PV=nRT for final conditions (263 K), $P = \frac{nRT}{V} = \frac{5.8328 \, \text{mol} \times 0.0821 \, \text{L atm/mol K} \times 263 \, \text{K}}{10.0 \, \text{L}} = 12.6 \, \text{atm}$.

Question 4

The molecules of different samples of an ideal gas have the same average kinetic energies, at the same

Accepted Answer

The average kinetic energy of a gas molecule is directly proportional to the temperature of the gas. Therefore, if different samples of an ideal gas have the same average kinetic energies, they must have the same temperature. The pressure, volume, and density of the gas do not affect the average kinetic energy of the gas molecules, as long as the temperature is held constant.

Question 5

5.00 g of hydrogen gas and 50.0 g of oxygen gas are introduced into an otherwise empty 9.00 L steel cylinder, and the hydrogen is ignited by an electric spark. If the reaction product is gaseous water and the temperature of the cylinder is maintained at 35ºC, what is the final gas pressure inside the cylinder

Accepted Answer

The answer of 5.00 g of hydrogen gas and 50.0...

Question 6

What mass of KClO₃ must be decomposed to produce 126 L of oxygen gas at 133^$\circ$C and 0.880 atm (The other reaction product is solid KCl.)

Accepted Answer

First, we need to write the balanced chemical equation for the decomposition of KClO3:
2 KClO3(s) → 2 KCl(s) + 3 O2(g)

According to the ideal gas law, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin. We can rearrange this equation to solve for n:
n = PV/RT

We are given the volume of oxygen gas produced (126 L), the temperature (133°F or 56.1°C = 329.3 K), and the pressure (0.880 atm). We can convert the temperature to Kelvin by adding 273.15:
T = 56.1°C + 273.15 = 329.3 K

Plugging in the values, we get:
n = (0.880 atm)(126 L)/(0.0821 L·atm/mol·K)(329.3 K) = 4.78 mol

From the balanced equation, we see that 2 moles of KClO3 produces 3 moles of O2. Therefore, the number of moles of KClO3 required is:
(4.78 mol O2) / (3 mol KClO3) = 1.59 mol KClO3

Finally, we can convert from moles to grams using the molar mass of KClO3:
mass = n × M
mass = (1.59 mol)(122.55 g/mol) = 194.6 g

However, we need to round this answer to the appropriate number of significant figures. 126 L has 3 significant figures, so our answer should also have 3 significant figures. The final answer is:
mass = 272 g

Question 7

What volume of O₂(g) at 810. mmHg pressure is required to react completely with a 4.50g sample of C(s) at 48^$\circ$C 2 C(s) + O₂(g) $\rarr$ 2 CO(g)

Accepted Answer

The answer of What volume of O₂(g) at 810. mmHg...

Question 8

Which of these gas molecules has the highest average kinetic energy at 25^$\circ$C

Accepted Answer

The average kinetic energy of a gas molecule is directly proportional to its temperature in accordance with the Kinetic Molecular Theory of Gases. However, the temperature provided in the question is the same for all the gases. Therefore, all the gas molecules have the same average kinetic energy.

Question 9

When active metals such as magnesium are immersed in acid solution, hydrogen gas is evolved. Calculate the volume of H₂(g) at 30.1^$\circ$C and 0.85 atm that can be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

Accepted Answer

The answer of When active metals such as magnesium are...

Question 10

10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final density of the gas mixture inside the vessel at 23ºC

Accepted Answer

The answer of 10.0 g of gaseous ammonia and 6.50...

Question 11

Which gas has molecules with the greatest average molecular speed at 25^$\circ$C

Accepted Answer

The average molecular speed of a gas at a given temperature is inversely proportional to the square root of its molar mass (Graham's law of effusion). CH₄ has the lowest molar mass among the options, thus its molecules have the greatest average speed at the same temperature.

Question 12

Calculate the volume of H₂(g) at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

Accepted Answer

First, we need to balance the equation: 
2HCl(aq) + Mg(s) → H2(g) + MgCl2(aq)

Next, we need to find the number of moles of HCl used: 
0.725 mol/L x 0.275 L = 0.199375 moles

According to stoichiometry, 2 moles of HCl produces 1 mole of H2, which means 0.199375 moles of HCl will produce 0.0996875 moles of H2.

We can use the ideal gas law to calculate the volume of H2 gas produced: 
PV = nRT 
V = nRT/P 
V = (0.0996875 mol)(0.08206 L·atm/mol·K)(273 K)/(2.00 atm) 
V = 1.12 L

Therefore, the correct answer is B) 1.12 L.

Question 13

What is the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 720 mmHg ?

Accepted Answer

The pressure of the gas is equal to the difference between the atmospheric pressure and the pressure exerted by the water column. The height of the water column is 708 mmHg (760 - 52) as the water exerts a pressure of 1 atm (760 mmHg) at the bottom of the tube. Therefore, the pressure of the gas is 720 - 708 = 12 mmHg. Choice A is incorrect as it is the pressure exerted by the water column alone. Choice C is incorrect as it is the same as atmospheric pressure. Choice D is incorrect as it is the sum of atmospheric and water column pressures. Choice E is incorrect as it is the atmospheric pressure alone.

Question 14

Determine the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 695 mmHg.

Accepted Answer

The answer of Determine the pressure of the gas trapped...

Question 15

Deviations from the ideal gas law are greater at

Accepted Answer

Deviations from the ideal gas law are greater at low temperatures and high pressures. This is because at high pressures, the volume of gas molecules becomes significant, and at low temperatures, the kinetic energy of the gas molecules decreases, making them more likely to stick together and form intermolecular forces. This causes the gas to deviate from ideal behavior.

Question 16

How many liters of oxygen gas at 153^$\circ$C and 0.820 atm can be produced by the decomposition of 22.4 g of solid KClO₃ (The other decomposition product is solid potassium chloride.)

Accepted Answer

The answer of How many liters of oxygen gas at...

Question 17

10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final gas pressure inside the vessel at 23ºC

Accepted Answer

1. Write the balanced chemical equation for the reaction:
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)

2. Convert the masses of ammonia and oxygen to moles using their molar masses:
nNH3 = 10.0 g / 17.031 g/mol = 0.587 mol
nO2 = 6.50 g / 31.999 g/mol = 0.203 mol

3. Determine the limiting reactant:
According to the balanced equation, 4 moles of NH3 react with 5 moles of O2. Therefore, the amount of NO produced is limited by the reactant that is present in the smaller stoichiometric amount. In this case, the limiting reactant is O2 because there are only 0.203 mol of O2, which is less than the amount required to react completely with 0.587 mol of NH3.

4. Calculate the amount of NO produced:
From the stoichiometry of the balanced equation, 5 moles of O2 react to produce 4 moles of NO. Therefore, the amount of NO produced is:
nNO = (4/5) × nO2 = (4/5) × 0.203 mol = 0.162 mol

5. Calculate the amount of H2O produced:
From the stoichiometry of the balanced equation, 4 moles of NH3 react to produce 6 moles of H2O. Therefore, the amount of H2O produced is:
nH2O = (6/4) × nNH3 = (6/4) × 0.587 mol = 0.880 mol

6. Calculate the total number of moles of gas in the vessel after the reaction:
nTotal = nNH3 + nO2 - nNO - nH2O
nTotal = 0.587 mol + 0.203 mol - 0.162 mol - 0.880 mol
nTotal = -0.252 mol (Note: The negative value means that the reaction produced more water vapor than the volume of the vessel can hold.)

7. Calculate the partial pressures of each gas using the ideal gas law:
PV = nRT
For NH3: PNH3 = (nNH3RT)/V = (0.587 mol × 0.0821 L·atm/mol·K × 296 K)/5.50 L = 0.211 atm
For O2: PO2 = (nO2RT)/V = (0.203 mol × 0.0821 L·atm/mol·K × 296 K)/5.50 L = 0.073 atm
For NO: PNO = (nNORT)/V = (0.162 mol × 0.0821 L·atm/mol·K × 296 K)/5.50 L = 0.059 atm
For H2O: PH2O = (nH2ORT)/V = (0.880 mol × 0.0821 L·atm/mol·K × 296 K)/5.50 L = 3.25 atm

8. Calculate the total pressure inside the vessel by adding the partial pressures:
PTotal = PNH3 + PO2 + PNO + PH2O
PTotal = 0.211 atm + 0.073 atm + 0.059 atm + 3.25 atm = 3.59 atm

9. Correct the total pressure for the excess water vapor:
Since the vessel can only hold a maximum volume of 5.50 L, any excess water vapor will condense and occupy a smaller volume than it would occupy at the same pressure if it were in the gas phase. The pressure of this condensed water vapor can be approximately calculated using the vapor pressure of water at 23ºC, which is 0.042 atm. Therefore, the corrected total pressure is:
PTotal,corr = PTotal - PH2O,excess
PH2O,excess = PH2O - Pvap(H2O,23ºC) = 3.25 atm - 0.042 atm = 3.21 atm
PTotal,corr = 3.59 atm - 3.21 atm = 0.38 atm

10. Round the final answer to two significant figures:
The final gas pressure inside the vessel at 23ºC is 0.38 atm, which is closest to choice D (3.67 atm), but none of the given choices is an acceptable answer.

Question 18

For a substance that remains a gas under the conditions listed, deviation from the ideal gas law would be most pronounced at

Accepted Answer

At lower temperatures and higher pressures, gases tend to deviate more from ideal gas behavior. Thus, the combination of -100°C and 4.0 atm in choice D represents conditions where deviation from the ideal gas law would be most pronounced.

Question 19

How many liters of chlorine gas at 25^$\circ$C and 0.950 atm can be produced by the reaction of 12.0 g of MnO₂ with excess HCl(aq) according to the following chemical equation MnO₂(s) + 4HCl(aq) $\rarr$MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

Accepted Answer

The answer of How many liters of chlorine gas at...

Question 20

If equal masses of O₂(g) and HBr(g) are in separate containers of equal volume and temperature, which one of these statements is true

Accepted Answer

The answer of If equal masses of O₂(g) and HBr(g)...

Quiz 5: Gases

Which statement is false

Liquid nitrogen has a density of 0.807 g/mL at -195.8 ^$\circ$C. If 1.00 L of N₂(l) is allowed to warm to 25^$\circ$C at a pressure of 1.00 atm, what volume will the gas occupy (R = 0.08206 Latm/Kmol)

9.45 g of liquid hexane (C₆H₁₄) is introduced into a 10.0 L vessel containing 13.15 atm of oxygen gas at 21ºC and ignited, yielding carbon dioxide and water. If the vessel is then cooled to -10.ºC, what will be the gas pressure inside the vessel

The molecules of different samples of an ideal gas have the same average kinetic energies, at the same

What mass of KClO₃ must be decomposed to produce 126 L of oxygen gas at 133^$\circ$C and 0.880 atm (The other reaction product is solid KCl.)

What volume of O₂(g) at 810. mmHg pressure is required to react completely with a 4.50g sample of C(s) at 48^$\circ$C 2 C(s) + O₂(g) $\rarr$ 2 CO(g)

Which of these gas molecules has the highest average kinetic energy at 25^$\circ$C

When active metals such as magnesium are immersed in acid solution, hydrogen gas is evolved. Calculate the volume of H₂(g) at 30.1^$\circ$C and 0.85 atm that can be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final density of the gas mixture inside the vessel at 23ºC

Which gas has molecules with the greatest average molecular speed at 25^$\circ$C

Calculate the volume of H₂(g) at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

What is the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 720 mmHg ?

Determine the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 695 mmHg.

Deviations from the ideal gas law are greater at

How many liters of oxygen gas at 153^$\circ$C and 0.820 atm can be produced by the decomposition of 22.4 g of solid KClO₃ (The other decomposition product is solid potassium chloride.)

10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final gas pressure inside the vessel at 23ºC

For a substance that remains a gas under the conditions listed, deviation from the ideal gas law would be most pronounced at

How many liters of chlorine gas at 25^$\circ$C and 0.950 atm can be produced by the reaction of 12.0 g of MnO₂ with excess HCl(aq) according to the following chemical equation MnO₂(s) + 4HCl(aq) $\rarr$ MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

If equal masses of O₂(g) and HBr(g) are in separate containers of equal volume and temperature, which one of these statements is true

Quiz 5: Gases

Which statement is false

Liquid nitrogen has a density of 0.807 g/mL at -195.8 ∘\circ∘ C. If 1.00 L of N2(l) is allowed to warm to 25 ∘\circ∘ C at a pressure of 1.00 atm, what volume will the gas occupy (R = 0.08206 L*atm/K*mol)

9.45 g of liquid hexane (C6H14) is introduced into a 10.0 L vessel containing 13.15 atm of oxygen gas at 21ºC and ignited, yielding carbon dioxide and water. If the vessel is then cooled to -10.ºC, what will be the gas pressure inside the vessel

The molecules of different samples of an ideal gas have the same average kinetic energies, at the same

What mass of KClO3 must be decomposed to produce 126 L of oxygen gas at 133 ∘\circ∘ C and 0.880 atm (The other reaction product is solid KCl.)

What volume of O2(g) at 810. mmHg pressure is required to react completely with a 4.50g sample of C(s) at 48 ∘\circ∘ C 2 C(s) + O2(g) →\rarr→ 2 CO(g)

Which of these gas molecules has the highest average kinetic energy at 25 ∘\circ∘ C

When active metals such as magnesium are immersed in acid solution, hydrogen gas is evolved. Calculate the volume of H2(g) at 30.1 ∘\circ∘ C and 0.85 atm that can be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final density of the gas mixture inside the vessel at 23ºC

Which gas has molecules with the greatest average molecular speed at 25 ∘\circ∘ C

Calculate the volume of H2(g) at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

What is the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 720 mmHg ?

Determine the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 695 mmHg.

Deviations from the ideal gas law are greater at

How many liters of oxygen gas at 153 ∘\circ∘ C and 0.820 atm can be produced by the decomposition of 22.4 g of solid KClO3 (The other decomposition product is solid potassium chloride.)

10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final gas pressure inside the vessel at 23ºC

For a substance that remains a gas under the conditions listed, deviation from the ideal gas law would be most pronounced at

How many liters of chlorine gas at 25 ∘\circ∘ C and 0.950 atm can be produced by the reaction of 12.0 g of MnO2 with excess HCl(aq) according to the following chemical equation MnO2(s) + 4HCl(aq) →\rarr→ MnCl2(aq) + 2H2O(l) + Cl2(g)

If equal masses of O2(g) and HBr(g) are in separate containers of equal volume and temperature, which one of these statements is true

Liquid nitrogen has a density of 0.807 g/mL at -195.8 ^$\circ$C. If 1.00 L of N₂(l) is allowed to warm to 25^$\circ$C at a pressure of 1.00 atm, what volume will the gas occupy (R = 0.08206 Latm/Kmol)

9.45 g of liquid hexane (C₆H₁₄) is introduced into a 10.0 L vessel containing 13.15 atm of oxygen gas at 21ºC and ignited, yielding carbon dioxide and water. If the vessel is then cooled to -10.ºC, what will be the gas pressure inside the vessel

What mass of KClO₃ must be decomposed to produce 126 L of oxygen gas at 133^$\circ$C and 0.880 atm (The other reaction product is solid KCl.)

What volume of O₂(g) at 810. mmHg pressure is required to react completely with a 4.50g sample of C(s) at 48^$\circ$C 2 C(s) + O₂(g) $\rarr$ 2 CO(g)

Which of these gas molecules has the highest average kinetic energy at 25^$\circ$C

When active metals such as magnesium are immersed in acid solution, hydrogen gas is evolved. Calculate the volume of H₂(g) at 30.1^$\circ$C and 0.85 atm that can be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

Which gas has molecules with the greatest average molecular speed at 25^$\circ$C

Calculate the volume of H₂(g) at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride.

How many liters of oxygen gas at 153^$\circ$C and 0.820 atm can be produced by the decomposition of 22.4 g of solid KClO₃ (The other decomposition product is solid potassium chloride.)

How many liters of chlorine gas at 25^$\circ$C and 0.950 atm can be produced by the reaction of 12.0 g of MnO₂ with excess HCl(aq) according to the following chemical equation MnO₂(s) + 4HCl(aq) $\rarr$ MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

If equal masses of O₂(g) and HBr(g) are in separate containers of equal volume and temperature, which one of these statements is true