Question 1

A sample of helium has a volume of 480 mL at 47.0°C and 740 mm Hg.The temperature is lowered to 22.0°C and the pressure to 625 mm Hg.What is the new volume?

Accepted Answer

We can use the combined gas law to solve for the new volume:

(P₁V₁/T₁) = (P₂V₂/T₂)

Substituting the given values:

(740 mmHg)(480 mL)/(47.0°C + 273.15) = (625 mmHg)(V₂)/(22.0°C + 273.15)

Solving for V₂:

V₂ = [(740 mmHg)(480 mL)/(47.0°C + 273.15)]/[(625 mmHg)/(22.0°C + 273.15)]

V₂ = 524 mL

Therefore, the new volume is 524 mL, which corresponds to choice C.

Question 2

A balloon originally had a volume of 4.39 L at 44°C and a pressure of 729 torr.To what temperature must the balloon be cooled to reduce its volume to 3.78 L if the pressure is constant?

Accepted Answer

We can use the combined gas law to solve this problem, as we are dealing with a constant pressure:

P1V1/T1 = P2V2/T2

We can rearrange this equation to solve for T2:

T2 = (P2V2*T1)/(P1V1)

Plugging in the given values:

T2 = (729 torr * 3.78 L * 44°C)/(4.39 L * 1 atm)

Note that we need to convert the pressure from torr to atm and the temperature from °C to K, using the conversions 1 atm = 760 torr and K = °C + 273.

T2 = (729/760 * 3.78 * (44 + 273))/(4.39)

T2 ≈ 273 K

Converting back to °C, we get:

T2 ≈ 0.0°C

Therefore, the balloon must be cooled to 0.0°C to reduce its volume to 3.78 L.

Question 3

How will the volume of a fixed sample of gas change if the pressure is doubled and its Celsius temperature is halved?

Accepted Answer

The relationship between pressure, volume, and temperature of a gas is given by the combined gas law, which is $P_1V_1/T_1 = P_2V_2/T_2$, where $P$ is pressure, $V$ is volume, and $T$ is temperature in Kelvin. The question does not specify the initial and final temperatures in Kelvin, which are necessary to determine the exact change in volume. Since the Celsius temperature is halved, without knowing the initial temperature in Celsius, we cannot convert it to Kelvin and thus cannot determine the exact change in volume.

Question 4

Which of the following is the definition of standard temperature and pressure?

Accepted Answer

Standard temperature and pressure (STP) is defined as 0 degrees Celsius (which is 273 K) and 1 atmosphere of pressure. 760 mm Hg is equivalent to 1 atmosphere, making option C correct.

Question 5

For the following reaction,if 11.2 L of nitrogen are reacted to form NH₃ at STP,how many liters of hydrogen will be required to completely consume all of the nitrogen? N₂ + 3H₂ → 2NH₃

Accepted Answer

The balanced chemical equation is N2 + 3H2 → 2NH3. According to the stoichiometry of the reaction, 1 mole of N2 reacts with 3 moles of H2. Since 1 mole of any gas at STP occupies 22.4 L, 11.2 L of N2 (which is 0.5 moles) would require 3 times that amount of H2 in moles, which is 1.5 moles. Therefore, 1.5 moles of H2 would occupy 1.5 * 22.4 L = 33.6 L.

Question 6

How will the volume of a fixed sample of gas change if its pressure is doubled and the Kelvin temperature is doubled?

Accepted Answer

According to the combined gas law, $V_1/T_1P_1 = V_2/T_2P_2$. If both the pressure and Kelvin temperature are doubled, the changes cancel each other out, leaving the volume unchanged.

Question 7

A sealed container with gas at 2.00 atm is heated from 20.0 K to 40.0 K.The new pressure is

Accepted Answer

According to Gay-Lussac's law, pressure is directly proportional to temperature when volume is constant. Doubling the temperature from 20.0 K to 40.0 K doubles the pressure from 2.00 atm to 4.00 atm.

Question 8

If the temperature of a 1.75 liter sample of gas is changed from 30.0°C to 20.0°C at constant pressure,what will be the new volume?

Accepted Answer

Using Charles's Law, we know that the volume of a gas is directly proportional to its temperature in Kelvin. We can convert the initial temperature of 30.0°C to Kelvin by adding 273.15:

Initial temperature: 30.0°C = 303.15 K 
Final temperature: 20.0°C = 293.15 K

Next, we can set up a proportion to find the new volume:

Initial volume / Initial temperature = Final volume / Final temperature

1.75 L / 303.15 K = Final volume / 293.15 K

Solving for Final volume:

Final volume = (1.75 L x 293.15 K) / 303.15 K = 1.69 L

Therefore, the new volume of the gas is 1.69 L. The correct answer is choice C.

Question 9

A 250.mL sample of gas at 1.00 atm and 20.0°C has the temperature increased to 40.0°C and the volume increased to 500.mL.What is the new pressure?

Accepted Answer

Using the combined gas law:

(P1V1)/T1 = (P2V2)/T2

P1 = 1.00 atm (Given)
V1 = 250 mL (Given)
T1 = 20.0°C + 273.15 K = 293.15 K (Conversion from °C to K)
V2 = 500 mL (Given)
T2 = 40.0°C + 273.15 K = 313.15 K (Conversion from °C to K)

Substituting these values into the equation:

(1.00 atm x 250mL) / 293.15K = (P2 x 500mL) / 313.15K

P2 = (1.00 atm x 250mL x 313.15K) / (293.15K x 500mL) = 0.534 atm

Therefore, the new pressure is 0.534 atm, which corresponds to choice C.

Question 10

According to Avogadro's Law,the volume of a gas will ________ as the ________ is increased while the ________ are held constant.

Accepted Answer

Avogadro's Law states that, at constant temperature and pressure, the volume of a gas is directly proportional to the number of moles of gas present. This means that as the number of moles of gas is increased, the volume of gas will also increase. Therefore, the correct choice is A.

Question 11

What will be the new volume when 128 mL of gas at 20.0°C is heated to 40.0°C while pressure remains unchanged?

Accepted Answer

According to Charles' law, at constant pressure, volume and temperature are directly proportional. Therefore, using the formula V1/T1 = V2/T2, we can calculate the new volume as follows:

V1 = 128 mL
T1 = 20.0°C + 273.15 = 293.15 K
T2 = 40.0°C + 273.15 = 313.15 K

V2 = (V1 x T2) / T1
V2 = (128 mL x 313.15 K) / 293.15 K
V2 = 136.9 mL

Rounding to the nearest whole number, the new volume is 137 mL. Therefore, the best choice is D.

Question 12

Which is a correct statement of Gay-Lussac's Law describing the behavior of a fixed amount of gas?

Accepted Answer

Gay-Lussac's Law states that the pressure of a gas is directly proportional to its temperature, at constant volume. As the temperature increases, the particles in the gas gain kinetic energy and move faster, colliding more frequently with the walls of the container, and thereby creating a higher pressure. Therefore, as temperature increases, pressure increases at constant volume.

Question 13

Chlorine gas is widely used to purify municipal water supplies and to treat swimming pool waters.Suppose that the volume of a particular sample of Cl₂ is 718 mL at 675 mmHg and 48°C,at what temperature (in °C)will the volume be 2.00 L if the pressure is 159 kPa?

Accepted Answer

The answer of Chlorine gas is widely used to purify...

Question 14

How many moles of gas are present in a 10.0 liter sample at STP?

Accepted Answer

At standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 liters. Therefore, to find the number of moles in a 10.0 liter sample, you divide the volume by the volume per mole: 10.0 liters / 22.4 liters/mole = 0.446 moles.

Question 15

A sample of gas has a volume of 135 mL at 0.600 atm.What would be the volume if the pressure is decreased to 0.200 atm while temperature is held constant?

Accepted Answer

Using Boyle's Law (P1V1 = P2V2), where P1 = 0.600 atm, V1 = 135 mL, and P2 = 0.200 atm, we solve for V2: V2 = (P1V1)/P2 = (0.600 atm * 135 mL) / 0.200 atm = 405 mL.

Question 16

Sketch a graph illustrating Charles's Law.Use a gas sample with a volume of 2.0 L at 0.75 atm and 27°C,and show at least two other points.

Accepted Answer

The answer of Sketch a graph illustrating Charles's Law.Use a...

Question 17

Consider a sample of helium and a sample of neon,both at 30.0°C and 1.5 atm.Both samples have a volume of 5.0 liters.Which statement concerning these samples is not true?

Accepted Answer

Given the conditions (same temperature, pressure, and volume), according to the Ideal Gas Law (PV = nRT), both samples must contain the same number of moles of gas (choice C is true). Since the number of moles is the same and Avogadro's Law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules, choice A is also true. Neon has a higher molar mass than helium, so even though they have the same number of moles, the neon sample would weigh more, making choice B false. Given that neon has a higher molar mass and the samples have the same volume, the density of neon would indeed be greater than that of helium, making choice D true.

Question 18

How many grams of N₂ are contained in an 11.2 liter sample at STP?

Accepted Answer

At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 liters. The molecular formula N₂ translates to N2S, which has a molar mass of (14.01*2) + 32.07 = 60.09 g/mol. Since 11.2 liters is half of 22.4 liters, it contains 0.5 moles of N2S. Therefore, the mass of N2S in grams is 0.5 moles * 60.09 g/mol = 30.045 g, which is not an option provided, indicating a misunderstanding in the interpretation of the formula or a mistake in the calculation. Correctly interpreting the formula as N2S and recalculating for a gas at STP should yield a result that matches one of the provided options, but based on standard interpretations, none of the options directly align with the expected outcome for N2S. Given the options and typical calculations for gases at STP, without a direct match, there seems to be a misunderstanding in the question's premise or a mistake in the provided options or the interpretation of the chemical formula.

Question 19

How many grams of O₂ are contained in a 25.0 L sample at 5.20 atm and 28.0°C?

Accepted Answer

The answer of How many grams of O₂ are contained...

Question 20

A 65 mL sample of argon gas has a temperature of 325°C.What will the temperature be in °C when the volume of the gas is decreased to 25 mL at constant pressure?

Accepted Answer

According to the combined gas law, P1V1/T1 = P2V2/T2, where P is pressure, V is volume, and T is temperature. As the pressure is constant, we can simplify the equation to V1/T1 = V2/T2.

So, V1/T1 = V2/T2

65mL/325°C = 25mL/T2

T2= (25mL x 325°C)/65mL

T2= 125°C

Therefore, the temperature will be 125°C when the volume is decreased to 25 mL.

Quiz 8: Gases, liquids, and Solids

A sample of helium has a volume of 480 mL at 47.0°C and 740 mm Hg.The temperature is lowered to 22.0°C and the pressure to 625 mm Hg.What is the new volume?

A balloon originally had a volume of 4.39 L at 44°C and a pressure of 729 torr.To what temperature must the balloon be cooled to reduce its volume to 3.78 L if the pressure is constant?

How will the volume of a fixed sample of gas change if the pressure is doubled and its Celsius temperature is halved?

Which of the following is the definition of standard temperature and pressure?

For the following reaction,if 11.2 L of nitrogen are reacted to form NH₃ at STP,how many liters of hydrogen will be required to completely consume all of the nitrogen? N₂ + 3H₂ → 2NH₃

How will the volume of a fixed sample of gas change if its pressure is doubled and the Kelvin temperature is doubled?

A sealed container with gas at 2.00 atm is heated from 20.0 K to 40.0 K.The new pressure is

If the temperature of a 1.75 liter sample of gas is changed from 30.0°C to 20.0°C at constant pressure,what will be the new volume?

A 250.mL sample of gas at 1.00 atm and 20.0°C has the temperature increased to 40.0°C and the volume increased to 500.mL.What is the new pressure?

According to Avogadro's Law,the volume of a gas will as the is increased while the are held constant.

What will be the new volume when 128 mL of gas at 20.0°C is heated to 40.0°C while pressure remains unchanged?

Which is a correct statement of Gay-Lussac's Law describing the behavior of a fixed amount of gas?

Chlorine gas is widely used to purify municipal water supplies and to treat swimming pool waters.Suppose that the volume of a particular sample of Cl₂ is 718 mL at 675 mmHg and 48°C,at what temperature (in °C) will the volume be 2.00 L if the pressure is 159 kPa?

How many moles of gas are present in a 10.0 liter sample at STP?

A sample of gas has a volume of 135 mL at 0.600 atm.What would be the volume if the pressure is decreased to 0.200 atm while temperature is held constant?

Sketch a graph illustrating Charles's Law.Use a gas sample with a volume of 2.0 L at 0.75 atm and 27°C,and show at least two other points.

Consider a sample of helium and a sample of neon,both at 30.0°C and 1.5 atm.Both samples have a volume of 5.0 liters.Which statement concerning these samples is not true?

How many grams of N₂ are contained in an 11.2 liter sample at STP?

How many grams of O₂ are contained in a 25.0 L sample at 5.20 atm and 28.0°C?

A 65 mL sample of argon gas has a temperature of 325°C.What will the temperature be in °C when the volume of the gas is decreased to 25 mL at constant pressure?

Quiz 8: Gases, liquids, and Solids

A sample of helium has a volume of 480 mL at 47.0°C and 740 mm Hg.The temperature is lowered to 22.0°C and the pressure to 625 mm Hg.What is the new volume?

A balloon originally had a volume of 4.39 L at 44°C and a pressure of 729 torr.To what temperature must the balloon be cooled to reduce its volume to 3.78 L if the pressure is constant?

How will the volume of a fixed sample of gas change if the pressure is doubled and its Celsius temperature is halved?

Which of the following is the definition of standard temperature and pressure?

For the following reaction,if 11.2 L of nitrogen are reacted to form NH3 at STP,how many liters of hydrogen will be required to completely consume all of the nitrogen? N2 + 3H2 → 2NH3

How will the volume of a fixed sample of gas change if its pressure is doubled and the Kelvin temperature is doubled?

A sealed container with gas at 2.00 atm is heated from 20.0 K to 40.0 K.The new pressure is

If the temperature of a 1.75 liter sample of gas is changed from 30.0°C to 20.0°C at constant pressure,what will be the new volume?

A 250.mL sample of gas at 1.00 atm and 20.0°C has the temperature increased to 40.0°C and the volume increased to 500.mL.What is the new pressure?

According to Avogadro's Law,the volume of a gas will ________ as the ________ is increased while the ________ are held constant.

What will be the new volume when 128 mL of gas at 20.0°C is heated to 40.0°C while pressure remains unchanged?

Which is a correct statement of Gay-Lussac's Law describing the behavior of a fixed amount of gas?

Chlorine gas is widely used to purify municipal water supplies and to treat swimming pool waters.Suppose that the volume of a particular sample of Cl2 is 718 mL at 675 mmHg and 48°C,at what temperature (in °C) will the volume be 2.00 L if the pressure is 159 kPa?

How many moles of gas are present in a 10.0 liter sample at STP?

A sample of gas has a volume of 135 mL at 0.600 atm.What would be the volume if the pressure is decreased to 0.200 atm while temperature is held constant?

Sketch a graph illustrating Charles's Law.Use a gas sample with a volume of 2.0 L at 0.75 atm and 27°C,and show at least two other points.

Consider a sample of helium and a sample of neon,both at 30.0°C and 1.5 atm.Both samples have a volume of 5.0 liters.Which statement concerning these samples is not true?

How many grams of N2 are contained in an 11.2 liter sample at STP?

How many grams of O2 are contained in a 25.0 L sample at 5.20 atm and 28.0°C?

A 65 mL sample of argon gas has a temperature of 325°C.What will the temperature be in °C when the volume of the gas is decreased to 25 mL at constant pressure?

For the following reaction,if 11.2 L of nitrogen are reacted to form NH₃ at STP,how many liters of hydrogen will be required to completely consume all of the nitrogen? N₂ + 3H₂ → 2NH₃

According to Avogadro's Law,the volume of a gas will as the is increased while the are held constant.

Chlorine gas is widely used to purify municipal water supplies and to treat swimming pool waters.Suppose that the volume of a particular sample of Cl₂ is 718 mL at 675 mmHg and 48°C,at what temperature (in °C) will the volume be 2.00 L if the pressure is 159 kPa?

How many grams of N₂ are contained in an 11.2 liter sample at STP?

How many grams of O₂ are contained in a 25.0 L sample at 5.20 atm and 28.0°C?