Question 1

A sample of N₂ gas is contaminated with a gas (A)of unknown molar mass.The partial pressure of each gas is known to be 200.torr at 25°C.The gases are allowed to effuse through a pinhole,and it is found that gas A escapes at 4 times the rate of N₂.The molar mass of gas A is:

Accepted Answer

Graham's law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass. Therefore, the molar mass of gas A is 4 times less than that of N2, which is 28 g/mol. Therefore, the molar mass of gas A is 7 g/mol.

Question 2

Which of the following statements is true concerning ideal gases?

Accepted Answer

The statement in option C is true, and the other statements are false. Option A is incorrect because temperature is related to the average kinetic energy, not velocity, of the gas particles. Option B is incorrect because the number of atoms in a gas sample is determined by Avogadro's law, which states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles. Option D is incorrect because ideal gases do not have intermolecular attractions.

Question 3

All the following are postulates of the kinetic-molecular theory of gases except:

Accepted Answer

The kinetic-molecular theory of gases does not state that each molecule has the same kinetic energy, but it does state that the average kinetic energy of gas molecules is directly proportional to the temperature of the gas.

Question 4

Complete the following: Because real gas particles have attraction for one another:

Accepted Answer

Real gases have attraction for one another, which causes them to deviate from ideal gas behavior, particularly at higher pressures and lower temperatures. Therefore, statement D correctly completes the sentence. The other statements are not necessarily true because real gases do not necessarily act most ideally at STP, and assuming gas particles have negligible volume is only a simplifying assumption used to derive the ideal gas law, but it is not necessarily true in reality. The statement about one mole of an ideal gas at STP having a volume of 22.4 L is true, but it does not directly relate to the effect of intermolecular attraction on real gases.

Question 5

Which of the following would have a higher rate of effusion than C₂H₂?

Accepted Answer

The answer of Which of the following would have a...

Question 6

The rate of effusion of an unknown gas was measured and found to be 11.9 mL/min.Under identical conditions,the rate of effusion of pure oxygen (O₂)gas is 14.0 mL/min.Based on this information,the identity of the unknown gas could be:

Accepted Answer

The answer of The rate of effusion of an unknown...

Question 7

According to the postulates of the kinetic theory of gases,the average speed of the molecules of a given gas is proportional to the

Accepted Answer

The kinetic theory of gases states that the average kinetic energy of gas molecules is proportional to the absolute temperature of the gas. Since kinetic energy is related to the square of the speed, this means the average speed of the molecules is proportional to the square root of the absolute temperature.

Question 8

Which of the following is true about the kinetic molecular theory?

Accepted Answer

According to the kinetic molecular theory, gas pressure is the result of the collisions of gas particles with the walls of the container.

Note: The other statements are incorrect. The volume of a gas particle is extremely small and is measured in nanometers. Gas particles can attract and repel each other depending on their intermolecular forces. Adding an ideal gas to a closed container does not necessarily cause an increase in temperature; it depends on the conditions of the system.

Question 9

Graham's law states that:

Accepted Answer

Graham's law states that the rates of effusion of gases are inversely proportional to the square roots of their molar masses. This means that lighter gases will diffuse or effuse more quickly than heavier gases. This law is a consequence of the kinetic theory of gases, which assumes that gas particles are in constant random motion and that their speed is proportional to the square root of their temperature and inversely proportional to their molar mass.

Question 10

Order the following in increasing rate of effusion: F₂,Cl₂,NO,NO₂,CH₄

Accepted Answer

Effusion rate is inversely proportional to molecular weight. Therefore, the smaller the molecular weight, the higher the effusion rate. The molecules are arranged in increasing order of molecular weight - CH₄ > NO₂ > NO > F₂ > Cl₂. Therefore, the increasing order of effusion rate is - Cl₂ < NO₂ < F₂ < NO < CH₄, and the correct choice is A.

Question 11

Which of the following is included as a postulate in the kinetic molecular theory of an ideal gas?

Accepted Answer

The kinetic molecular theory of gases includes the postulate that all collisions between gas molecules are perfectly elastic, meaning that there is no net loss of kinetic energy in the system during collisions.

Question 12

Which statement is inconsistent with the kinetic theory of an ideal gas?

Accepted Answer

According to the kinetic theory of an ideal gas, when two gas molecules collide, they exchange energy but do not create energy. Therefore, it is not possible for both molecules to gain kinetic energy during a collision. This statement is inconsistent with the kinetic theory.

Question 13

Which of the following effects will make PV/nRT less than one for a real gas?

Accepted Answer

The gas molecules attracting each other will cause them to be pulled closer together than they would be in an ideal gas. This decreases the volume and increases the pressure, resulting in a smaller value of PV/nRT.

Question 14

The van der Waals equation,nRT = [P + a(n/V)²] (V - nb),incorporates corrections to the ideal gas law in order to account for the properties of real gases.One of the corrections accounts for

Accepted Answer

The correction for finite volume of molecules is incorporated through the factor nb in the van der Waals equation. The other choices do not account for this correction.

Question 15

Hydrogen and chlorine gases react to form HCl.You and a friend are on opposite sides of a long hallway,you with H₂ and your friend with Cl₂.You both want to form HCl in the middle of the room.Which of the following is true?

Accepted Answer

The answer of Hydrogen and chlorine gases react to form...

Question 16

Which of the following properties of a real gas is related to the b coefficient in the van der Waals equation?

Accepted Answer

The b coefficient in the van der Waals equation accounts for the volume occupied by the gas molecules themselves, acknowledging that real gas particles have finite volume.

Question 17

The diffusion of a gas is faster than the effusion of a gas.

Accepted Answer

Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration, while effusion is the process by which gas molecules pass through a tiny opening from an area of high pressure to an area of lower pressure. The rate of effusion is generally faster than diffusion because effusion involves movement through a small opening, which can occur more rapidly than the spreading out of gas molecules in diffusion.

Question 18

Consider the following containers,one with helium at 27°C and the other with argon at 27°C.   Which of the following statements are true?

Accepted Answer

The answer of Consider the following containers,one with helium at...

Question 19

Calculate the ratio of the effusion rates of N₂ and N₂O.

Accepted Answer

The effusion rate is inversely proportional to the square root of the molar mass. The molar mass of N₂ is 680 g/mol and the molar mass of N₂O is 752 g/mol. Therefore, the ratio of effusion rates would be: (sqrt(752/680)) = 1.25 Hence, the answer is (C).

Question 20

At the same temperature,lighter molecules have a higher average kinetic energy than heavier molecules.

Accepted Answer

At the same temperature, all molecules, regardless of their mass, have the same average kinetic energy. This is because temperature is a measure of the average kinetic energy of the molecules in a substance.

Quiz 5: Gases

A sample of N₂ gas is contaminated with a gas (A) of unknown molar mass.The partial pressure of each gas is known to be 200.torr at 25°C.The gases are allowed to effuse through a pinhole,and it is found that gas A escapes at 4 times the rate of N₂.The molar mass of gas A is:

Which of the following statements is true concerning ideal gases?

All the following are postulates of the kinetic-molecular theory of gases except:

Complete the following: Because real gas particles have attraction for one another:

Which of the following would have a higher rate of effusion than C₂H₂?

The rate of effusion of an unknown gas was measured and found to be 11.9 mL/min.Under identical conditions,the rate of effusion of pure oxygen (O₂) gas is 14.0 mL/min.Based on this information,the identity of the unknown gas could be:

According to the postulates of the kinetic theory of gases,the average speed of the molecules of a given gas is proportional to the

Which of the following is true about the kinetic molecular theory?

Graham's law states that:

Order the following in increasing rate of effusion: F₂,Cl₂,NO,NO₂,CH₄

Which of the following is included as a postulate in the kinetic molecular theory of an ideal gas?

Which statement is inconsistent with the kinetic theory of an ideal gas?

Which of the following effects will make PV/nRT less than one for a real gas?

The van der Waals equation,nRT = [P + a(n/V) ²] (V - nb) ,incorporates corrections to the ideal gas law in order to account for the properties of real gases.One of the corrections accounts for

Hydrogen and chlorine gases react to form HCl.You and a friend are on opposite sides of a long hallway,you with H₂ and your friend with Cl₂.You both want to form HCl in the middle of the room.Which of the following is true?

Which of the following properties of a real gas is related to the b coefficient in the van der Waals equation?

The diffusion of a gas is faster than the effusion of a gas.

Consider the following containers,one with helium at 27°C and the other with argon at 27°C. Which of the following statements are true?

Calculate the ratio of the effusion rates of N₂ and N₂O.

At the same temperature,lighter molecules have a higher average kinetic energy than heavier molecules.

Quiz 5: Gases

A sample of N2 gas is contaminated with a gas (A) of unknown molar mass.The partial pressure of each gas is known to be 200.torr at 25°C.The gases are allowed to effuse through a pinhole,and it is found that gas A escapes at 4 times the rate of N2.The molar mass of gas A is:

Which of the following statements is true concerning ideal gases?

All the following are postulates of the kinetic-molecular theory of gases except:

Complete the following: Because real gas particles have attraction for one another:

Which of the following would have a higher rate of effusion than C2H2?

The rate of effusion of an unknown gas was measured and found to be 11.9 mL/min.Under identical conditions,the rate of effusion of pure oxygen (O2) gas is 14.0 mL/min.Based on this information,the identity of the unknown gas could be:

According to the postulates of the kinetic theory of gases,the average speed of the molecules of a given gas is proportional to the

Which of the following is true about the kinetic molecular theory?

Graham's law states that:

Order the following in increasing rate of effusion: F2,Cl2,NO,NO2,CH4

Which of the following is included as a postulate in the kinetic molecular theory of an ideal gas?

Which statement is inconsistent with the kinetic theory of an ideal gas?

Which of the following effects will make PV/nRT less than one for a real gas?

The van der Waals equation,nRT = [P + a(n/V) 2] (V - nb) ,incorporates corrections to the ideal gas law in order to account for the properties of real gases.One of the corrections accounts for

Hydrogen and chlorine gases react to form HCl.You and a friend are on opposite sides of a long hallway,you with H2 and your friend with Cl2.You both want to form HCl in the middle of the room.Which of the following is true?

Which of the following properties of a real gas is related to the b coefficient in the van der Waals equation?

The diffusion of a gas is faster than the effusion of a gas.

Consider the following containers,one with helium at 27°C and the other with argon at 27°C. Which of the following statements are true?

Calculate the ratio of the effusion rates of N2 and N2O.

At the same temperature,lighter molecules have a higher average kinetic energy than heavier molecules.

A sample of N₂ gas is contaminated with a gas (A) of unknown molar mass.The partial pressure of each gas is known to be 200.torr at 25°C.The gases are allowed to effuse through a pinhole,and it is found that gas A escapes at 4 times the rate of N₂.The molar mass of gas A is:

Which of the following would have a higher rate of effusion than C₂H₂?

The rate of effusion of an unknown gas was measured and found to be 11.9 mL/min.Under identical conditions,the rate of effusion of pure oxygen (O₂) gas is 14.0 mL/min.Based on this information,the identity of the unknown gas could be:

Order the following in increasing rate of effusion: F₂,Cl₂,NO,NO₂,CH₄

The van der Waals equation,nRT = [P + a(n/V) ²] (V - nb) ,incorporates corrections to the ideal gas law in order to account for the properties of real gases.One of the corrections accounts for

Hydrogen and chlorine gases react to form HCl.You and a friend are on opposite sides of a long hallway,you with H₂ and your friend with Cl₂.You both want to form HCl in the middle of the room.Which of the following is true?

Calculate the ratio of the effusion rates of N₂ and N₂O.