Gas Pressure Activity Questions

Gas Pressure Activity

Objective: Pressure is caused by the number of collisions between molecules and the force of these collisions. When there are more collisions, the pressure is higher. There are three things that can affect the number of collisions.

            1) size of the container

            2) temperature

            3) number of molecules

You will look at how these three factors affect the number of collisions and therefore affect the pressure of a gas.

Procedure: For each of the following parts, you will need a long rope and four students to hold the rope in a square shape. Each student holding the rope will count the number of “gas molecules” (students) that collide with the wall of the container during a time period of one minute for each trial.

Gas molecules should remember the following:

1)     Gas molecules travel in straight path until acted upon by the wall of the container or another gas molecule. They do not turn to avoid or cause a collision.

2)     Gas molecules move at constant random motion. So you should not change your speed or stop during the duration of a trial.

3)     Gas molecules are not attracted to or repelled by each other. So you should not change directions to hit your classmates. 

1. DATA & ACTIVITY

PART A

Container size and pressure: Gas molecules should move at room temperature.

Container Size	Number of collisions         Trial 1                              Trial 2                                Average
Small container
Large container

PART B

Temperature and pressure: Gas molecules should speed walk for high temperature and walk slowly for low temperature.

Temperature	Number of collisions         Trial 1                                Trial 2                                 Average
High Temperature
Low Temperature

PART C

Number of molecules and pressure

Number of Molecules	Number of collisions         Trial 1                               Trial 2                             Average
5 molecules
10 molecules

2. Analyze your data:

1)      What two things cause pressure in gases?

2)      Out of the three factors that affect pressure, which do you think would affects the pressure the most? Why?

3)      As you increase the size of a container, what happens to pressure?

4)      As you decrease the number of gas particles, what happens to pressure?

5)      As you increase the temperature, what happens to pressure?

6)      As temperature decreases, what do you think would happen to the volume of a balloon?

7)      Draw two pictures each of Part A & Part C, drawing two boxes for each of the two different situations in the activity. Make sure to show the molecules in the boxes accurately.

 

Part A                                                                                    Large

Small                                                                                     container

container

Part C                                                                                    10

5                                                                                              molecules

molecules