Investigating Pressure Laws

Authors Avatar

Chemistry Lab: Pressure Laws                                               Samia Murgham 11N

Introduction:

Aim: To investigate the relationship between temperature and pressure of a gas, by heating/cooling the reagent flasks full of air and measuring the temperature and pressure of the gas inside.

General background: Molecules of a gas are in constant motion. Gas pressure is a measure of the number of collisions of molecules with the walls of the container. The velocity and the number of collisions changes when the temperature of the gas changes (increases or decreases) In this experiment, the relationship between the temperature of a gas sample and the pressure it exerts will be investigated. Samples of air will be placed in water baths of varying temperature. Pressure will be monitored with a pressure sensor and temperature will be monitored using a temperature probe. Pressure and temperature data pairs will be collected during the experiment and then analyzed. From the data and graph, you will determine what kind of mathematical relationship exists between the pressure and absolute temperature of a confined gas.

Hypothesis: In a closed container the air pressure will rise if you increase the temperature,

because the molecules bounce off each other and the walls of the container with greater speed.

Prediction: as the temperature cools down in this experiment, we expect to see the pressure readings decrease gradually.

Independent variable: temperature of the water bath, as it is altered throughout the experiment in Degrees Celsius.

Dependent variable: Pressure, as it is the variable that is being measured in kPa.

Join now!

Controlled variables: the type of gas in the flask is kept the same and the rubber bung was never removed from the flask once the experiment had been started. The volume of the gas sample and the number of molecules it contains is kept constant.

Materials and Methods:

Diagram of Setup:

Apparatus: pressure sensor, temperature probe, flask with rubber bung, water bath (large beaker), ice blocks, hot water from kettle.

Procedure: First, the pressure in the flask will be measured at room temperature and then the flask will be placed ...

This is a preview of the whole essay