Page 114 - Science Coursebook

8.4 Temperature and the rate of reaction

Activity 8.4C

The effect of temperature on the rate of reaction – investigation
SE When your teacher has checked your plan, you can carry out your investigation.

Questions
A5 How did you make sure this was a fair test?
A6 Plot a graph of your results.
A7 Describe the relationship between the temperature and the rate of reaction.

Here is a graph of some typical results for
the rate of the reaction between marble 40 °C
chips and hydrochloric acid. This was volume of
carried out as in the previous topic. 30 °C
hydrogen
You can see from the graph that you do produced
not get any more of the product (carbon
dioxide gas) at the higher temperature. You
get the same volume of gas, but in less time.
time
Questions
A+I 1 How can you tell which line shows the faster reaction?
A+I 2 If you did the same experiment at 50 °C what would the line on the graph be like?

Explaining the effect of temperature

Particles move all the time. When the temperature of the reaction is increased the
particles move faster. They collide more often, and with more energy.

Reaction at 30 °C. Reaction at 40 °C.

Summary
• As the temperature is increased the rate of reaction increases.
• When particles have more energy they move faster, and collide more
often and with greater energy.

112 8 Rates of reaction