Question 1

What is the volume occupied by an 8.00 gram sample of molecular oxygen at STP?

Accepted Answer

The answer of What is the volume occupied by an...

Question 2

A certain quantity of neon gas is under 1.05 atm pressure at 303 K in a 10.0 L vessel. How many moles of neon are present?

Accepted Answer

We can use the Ideal Gas Law formula: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in Kelvin.

Rearranging the formula to solve for n, we get: n = PV/RT

Plugging in the given values, we get: 
n = (1.05 atm)(10.0 L)/(0.08206 L·atm/mol·K)(303 K)
n = 0.422 mol

Therefore, the answer is choice C, 0.422 mol.

Question 3

Which of the following is a mathematical statement of the ideal gas law?

Accepted Answer

The ideal gas law is mathematically represented by the equation PV = nRT, where P is the pressure of the gas, V is its volume, n is the amount of gas (in moles), R is the universal gas constant, and T is the temperature in Kelvin.

Question 4

Standard temperature and pressure are which of the following?

Accepted Answer

Standard temperature and pressure (STP) is defined as 273.15 K (0 °C) and 1 atm (101.325 kPa).

Question 5

A sample of carbon dioxide occupies 22.4 L at STP. Which of the following statements apply to the sample?

Accepted Answer

At STP, 1 mole of any gas occupies 22.4 L. Therefore, the sample of carbon dioxide contains 1 mole of carbon dioxide. Since 1 mole of carbon dioxide contains 6.02 × 10²³ molecules and 6.02 × 10²³ carbon atoms, both statements a and b are correct.

Question 6

Which of the following could be a correct set of units for the ideal gas law constant, R?

Accepted Answer

The ideal gas law is PV = nRT, where P is the pressure in atmospheres, V is the volume in liters, n is the number of moles, T is the temperature in Kelvin, and R is the ideal gas constant. Rearranging the equation, R = (PV)/(nT). Therefore, the units of R must be (pressure x volume) / (moles x temperature). Choice A is incorrect because it includes only volume and moles, but not pressure or temperature. Choice B is incorrect because it includes pressure and volume, but not temperature. Choice D is incorrect because it includes all four quantities, but not divided by each other. Choice C is the correct answer because it includes all four quantities and they are all properly divided by each other.

Question 7

Which of the following is called standard temperature and pressure?

Accepted Answer

Standard temperature and pressure (STP) is defined as 0°C (273.15 K) and 1 atmosphere (1 atm) of pressure. Option A represents these values. Option B represents a different temperature scale and option C represents absolute zero, which is not the same as STP.

Question 8

If a 7.00 gram sample of molecular nitrogen at 10. °C occupies 2.50 L, what is the pressure of the sample?

Accepted Answer

Using the ideal gas law, PV = nRT, where n = mass/molar mass. For N2, molar mass = 28.02 g/mol. Calculate n = 7.00 g / 28.02 g/mol = 0.25 mol. Convert temperature to Kelvin: 10°C = 283 K. Use R = 0.0821 L·atm/mol·K. Solve for P: P = nRT/V = (0.25 mol)(0.0821 L·atm/mol·K)(283 K) / 2.50 L = 2.32 atm.

Question 9

If an 8.00 gram sample of molecular oxygen at 1.00 atm pressure occupies 3.00 L, what is the temperature of the sample?

Accepted Answer

To solve for temperature, we can use the ideal gas law: PV = nRT. First, we need to convert grams of oxygen to moles. We can use the molar mass of oxygen (32.00 g/mol) to do this: 8.00 g / 32.00 g/mol = 0.25 mol. Next, we can plug in the values we have: (1.00 atm)(3.00 L) = (0.25 mol)(R)(T), where R is the gas constant. Solving for T gives us T = (1.00 atm)(3.00 L) / (0.25 mol)(R). Using the value for R, we get T = 120 K. However, the question is asking for temperature in Celsius or Kelvin, so we need to convert. 120 K - 273.15 = -153.15°C. Since we want the temperature to be positive, we use the Kelvin temperature, which is 120 K. Therefore, the answer is B) 146 K.

Question 10

Which law relates the volume and number of molecules of a gas under conditions of constant temperature and pressure?

Accepted Answer

Avogadro's law states that at the same temperature and pressure, equal volumes of gases contain the same number of molecules, regardless of their chemical nature and physical conditions. Therefore, the volume of a gas is directly proportional to the number of molecules of gas present under constant temperature and pressure.

Question 11

A student has equal-volume samples of three gases. All the gases are at the same temperature and pressure. If the three gases are O₂, CO₂, NH₃, which sample contains the largest number of atoms?

Accepted Answer

The number of atoms in a sample is determined by the number of moles of the gas and Avogadro's constant (6.02×1023 mol-1). By comparing the molecular formulas, we can see that the samples contain 1 mole each of the gases, which means they all contain the same number of moles. However, the number of atoms in each mole is different due to the different compositions of the molecules. O₂ contains 15 atoms per mole (1 sulfur, 2 boron, 12 oxygen) CO₂ contains 14 atoms per mole (1 carbon, 1 sulfur, 2 boron, 12 oxygen) NH₃ contains 16 atoms per mole (1 nitrogen, 1 sulfur, 1 boron, 13 oxygen) Therefore, NH₃ has the largest number of atoms per mole and, consequently, per equal-volume sample.

Question 12

A student obtained experimental data and plotted it graphically, but forgot to label the axes of the graph. How should the axes of the graph shown here be labeled?

Accepted Answer

The answer of A student obtained experimental data and plotted...

Question 13

If 2.00 moles of NO gas occupies 10.0 L at 295 K, what is the pressure of the gas in atmospheres?

Accepted Answer

Using the ideal gas law, PV = nRT, where P is pressure, V is volume, n is moles, R is the ideal gas constant (0.0821 L·atm/mol·K), and T is temperature in Kelvin. Plugging in the values: P = (2.00 moles * 0.0821 L·atm/mol·K * 295 K) / 10.0 L = 4.84 atm.

Question 14

Which of the following will occur if the temperature of a gas is decreased from 60 K to 30 K at constant pressure?

Accepted Answer

According to Charles's Law, at constant pressure, the volume of a gas is directly proportional to its absolute temperature. Therefore, if the temperature is decreased from 60 K to 30 K, the volume will be halved.

Question 15

A student has equal-volume samples of three gases. All the gases are at the same temperature and pressure. If the three gases are O₂, CO₂, NH₃, which sample contains the largest number of molecules?

Accepted Answer

According to Avogadro's law, equal volumes of gases at the same temperature and pressure contain the same number of molecules.

Question 16

A sample of carbon dioxide occupies 22.4 L at STP. Which of the following statements apply to the sample?

Accepted Answer

At STP, 1 mole of any gas occupies 22.4 L. Carbon dioxide has a molar mass of 44 g/mol, so at STP 44 g of carbon dioxide occupies 22.4 L. This means that 1 mole of carbon dioxide (which weighs 44 g) occupies 22.4 L. Therefore, the sample of carbon dioxide in the question must contain 6.02 × 10^23 molecules, which is choice C. Choice A is incorrect because it refers to atoms rather than molecules. Choice B is incorrect because it refers to oxygen atoms rather than carbon dioxide molecules.

Question 17

Which of the following will occur if the temperature of a gas is increased from 20 K to 40 K at constant pressure?

Accepted Answer

According to Charles's Law, at constant pressure, the volume of a gas is directly proportional to its temperature in Kelvin. Doubling the temperature from 20 K to 40 K will double the volume.

Question 18

A gas is expanded from an initial volume of 20.5 L at 0.92 atm at 23 °C to a final volume of 34.6 L. During the expansion the gas cools to 12 °C. What is the final pressure?

Accepted Answer

Using the combined gas law: (P1 * V1) / T1 = (P2 * V2) / T2, where temperatures are in Kelvin. Convert temperatures: 23°C = 296K, 12°C = 285K. Solve for P2: P2 = (P1 * V1 * T2) / (V2 * T1) = (0.92 atm * 20.5 L * 285 K) / (34.6 L * 296 K) ≈ 0.52 atm.

Question 19

Which of the following is a mathematical statement of the ideal gas law?

Accepted Answer

The ideal gas law is PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the gas constant, and T is the temperature. By rearranging the equation, we get PV/RT = n, which is equivalent to choice B.

Question 20

Which of the following will occur if the temperature of a gas is decreased from 60°C to 30°C at constant pressure?

Accepted Answer

According to Charles's Law, the volume of a gas is directly proportional to its temperature in Kelvin at constant pressure. Decreasing the temperature from 60°C to 30°C will cause a slight decrease in volume.

Quiz 5: Gases, Liquids, and Solids

What is the volume occupied by an 8.00 gram sample of molecular oxygen at STP?

A certain quantity of neon gas is under 1.05 atm pressure at 303 K in a 10.0 L vessel. How many moles of neon are present?

Which of the following is a mathematical statement of the ideal gas law?

Standard temperature and pressure are which of the following?

A sample of carbon dioxide occupies 22.4 L at STP. Which of the following statements apply to the sample?

Which of the following could be a correct set of units for the ideal gas law constant, R?

Which of the following is called standard temperature and pressure?

If a 7.00 gram sample of molecular nitrogen at 10. °C occupies 2.50 L, what is the pressure of the sample?

If an 8.00 gram sample of molecular oxygen at 1.00 atm pressure occupies 3.00 L, what is the temperature of the sample?

Which law relates the volume and number of molecules of a gas under conditions of constant temperature and pressure?

A student has equal-volume samples of three gases. All the gases are at the same temperature and pressure. If the three gases are O2, CO2, NH3, which sample contains the largest number of atoms?

A student obtained experimental data and plotted it graphically, but forgot to label the axes of the graph. How should the axes of the graph shown here be labeled?

If 2.00 moles of NO gas occupies 10.0 L at 295 K, what is the pressure of the gas in atmospheres?

Which of the following will occur if the temperature of a gas is decreased from 60 K to 30 K at constant pressure?

A student has equal-volume samples of three gases. All the gases are at the same temperature and pressure. If the three gases are O2, CO2, NH3, which sample contains the largest number of molecules?

A sample of carbon dioxide occupies 22.4 L at STP. Which of the following statements apply to the sample?

Which of the following will occur if the temperature of a gas is increased from 20 K to 40 K at constant pressure?

A gas is expanded from an initial volume of 20.5 L at 0.92 atm at 23 °C to a final volume of 34.6 L. During the expansion the gas cools to 12 °C. What is the final pressure?

Which of the following is a mathematical statement of the ideal gas law?

Which of the following will occur if the temperature of a gas is decreased from 60°C to 30°C at constant pressure?

A student has equal-volume samples of three gases. All the gases are at the same temperature and pressure. If the three gases are O₂, CO₂, NH₃, which sample contains the largest number of atoms?

A student has equal-volume samples of three gases. All the gases are at the same temperature and pressure. If the three gases are O₂, CO₂, NH₃, which sample contains the largest number of molecules?