The Effect of Acid Concentration on the Rate of Reaction

The Effect of Acid Concentration on the Rate of Reaction

Introduction:

We are going to investigate the effect of Acid Concentration on the

Rate of Chemical Reaction. We are going to use the combination of

Hydrochloric Acid and Calcium Carbonate as the reactants:

[IMAGE][IMAGE]

[IMAGE]Calcium Carbonate + Hydrochloric Acid Calcium Chloride + Water

+ Carbon Dioxide

Prediction

I predict that the greater the concentration of acid the greater the

rate of chemical reaction i.e. the rate of reaction will be directly

proportional to the concentration of acid.

This means that if I were to double the concentration of acid the rate

of reaction would also double, halving the time taken.

In order to generate a more accurate picture I have constructed a

series of graphs highlighting my above statements. I have used a

relative scale, following my prediction, in order to calculate the

rate and therefore time taken.

Concentration (Molar)

Rate

Time Taken

2.0

5

0.2

1.6

4

0.25

1.2

3

[IMAGE]

0.8

2

0.5

0.4

1

1

[IMAGE]

This graph shows the concept of how the greater the acid concentration

the greater the rate of reaction. The idea being that with a

concentration of 0 moles the rate would be infinity, comparatively by

increasing the concentration of acid, the more instantaneous the

reaction becomes.

[IMAGE]

This graph represents the relationship that exists between acid

concentration and rate; by increasing the acid concentration the rate

is increasing as well. The straight line indicates the direct

relationship; double the acid concentration you double the rate of

reaction.

Justification

The Collision theory justifies the prediction of increased acid

concentration causing increased rate of reaction by relating to the

concept of proportional molecular content; i.e. if there are more acid

molecules they are more likely to collide with those of the Calcium