Question

the diagrams above use arrows to represent the speed of a gas particle. which of the diagrams best represents the speed of the particles of a gas at a fixed temperature, and why? a. diagram 1, because all the particles have the same speed. b. diagram 1, because the particles are moving in different directions. c. diagram 2, because the particles have a net kinetic energy of zero. d. diagram 2, because the particles have a variety of different speeds. 11. the two gas samples represented in the graph to the left are at the same temperature. which of the following statements about the gases is correct? a. the molecules of gas z have a higher average kinetic energy than the molecules of gas x. b. there are fewer molecules in the sample of gas z than in the sample of gas x. c. gas z has a smaller molar mass than gas x. d. gas z has a greater molar mass than gas x.

Explanation:

Step1: Recall kinetic - theory of gases

In the kinetic - theory of gases, at a fixed temperature, gas particles have a distribution of speeds and move in different directions.

Step2: Analyze Diagram 1 and Diagram 2

Diagram 1 shows particles moving in different directions with a variety of speeds. Diagram 2 shows particles all with the same speed, which is not consistent with the kinetic - theory of gases at a fixed temperature.

Step3: Analyze the speed - distribution graph

The root - mean - square speed of gas molecules is given by $v_{rms}=\sqrt{\frac{3RT}{M}}$, where $R$ is the gas constant, $T$ is the temperature, and $M$ is the molar mass. At the same temperature, a gas with a smaller molar mass has a higher root - mean - square speed. From the graph, gas X has a higher average speed than gas Z at the same temperature, so gas Z has a greater molar mass than gas X.

Answer:

1. D
2. D