Question

4 according to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas?
a the collisions between the gas particles cannot result in a transfer of energy between the particles.
b the motion of the gas particles is random and straight-line.
c the separation between the gas particles is smaller than the size of the gas particles themselves.
d the force of attraction between the gas particles is strong.

1. a sample of a gas is contained in a closed rigid cylinder. according to the kinetic molecular theory, what occurs when the gas inside the cylinder is heated?

a. the rate of collisions between gas molecules decreases.
b. the number of gas molecules increases.
c. the average velocity of the gas molecules increases.
d. the volume of the gas decreases.

1. an assumption of the kinetic theory of gases is that the particles of a gas have —

a. strong attraction for each other and significant volume.
b. little attraction for each other and significant volume.
c. little attraction for each other and insignificant volume.
d. strong attraction for each other and insignificant volume.

Explanation:

Question 4

• Option A: Collisions between ideal gas particles are elastic, meaning energy is transferred (though total kinetic energy is conserved), so A is wrong.
• Option B: Kinetic molecular theory states gas particles move randomly in straight lines until they collide, so B is correct.
• Option C: In ideal gases, particle separation is much larger than particle size, so C is wrong.
• Option D: Ideal gas particles have negligible intermolecular forces, so D is wrong.

• Option A: Heating increases particle energy and speed, so collision rate should increase, not decrease. A is wrong.
• Option B: The gas is in a closed cylinder, so the number of molecules (moles) remains constant. B is wrong.
• Option C: Heating increases the average kinetic energy of gas molecules, and since kinetic energy is related to velocity ($KE=\frac{1}{2}mv^{2}$), average velocity increases. C is correct.
• Option D: The cylinder is rigid, so volume is constant. D is wrong.

• Kinetic theory of gases assumptions: Gas particles have negligible (insignificant) volume and little to no intermolecular attraction (so they move freely).
• Option A: Wrong, as attraction is little and volume is insignificant.
• Option B: Wrong, volume is insignificant.
• Option C: Correct, matches the assumptions (little attraction, insignificant volume).
• Option D: Wrong, attraction is little, not strong.

Answer:

B. The motion of the gas particles is random and straight - line.

Question 5