Gas Pressure

Introduction

An important property of a gas is its pressure. Pressure is the force exerted by a gas over an area, such as when you blow up a balloon or inflate a bicycle tire. The pressure of a gas is influenced by its temperature; for example, the pressure may become dangerously high inside a spray-paint can if it is left in the sun.

When two or more chemicals react, gases may be produced. The rate at which the chemical reaction takes place can be affected by a number of different factors including temperature. In this activity, you will see how temperature affects the rate at which an effervescent antacid tablet reacts with water and releases a gas. The rate at which the reaction occurs is directly proportional to the rate of gas production. You will use a Gas Pressure Sensor to measure this rate by recording the pressure variation in a closed container as the reaction proceeds.

Objectives

• Use a Gas Pressure Sensor and NXT to measure pressure changes during a chemical reaction.
• Model pressure data using a linear function.
• Use the concept of slope to describe the effect of temperature on chemical reaction rates.