Page 117 - Science Coursebook

8.5 Concentration and the rate of reaction

Questions

A+I 1 How can you tell which line on the graph shows the faster reaction?
A+I 2 If you did the same experiment with even less concentrated acid what would
the line on the graph be like?

Explaining the effect of concentration

Again, we can use particle theory to help explain these results.

The higher the concentration of hydrochloric acid, the more hydrochloric acid
particles there are in a given amount of space. This means that there will be more
frequent collisions between hydrochloric acid particles and calcium carbonate
particles.

hydrochloric acid particle

marble particle

beaker
containing
acid

marble chip

Reaction in dilute acid. Reaction in acid that is twice
as concentrated.

Summary
• As the concentration of reactants is increased, the rate of reaction
is increased.
• When there are more particles in a given volume they are more likely to
collide with each other.

8 Rates of reaction 115