Factors That Affect The Rates Of Reaction

Background Information

Chemical reactions only happen when particles of two different substances collide with each other. The two substances at the start are known as the reactants and when they react what is produced is known as the products. Three ways of speeding the reaction up are:

Increasing Temperature

* The particles only have little energy because they are cold so fewer collisions take place.

* The particles have lots of energy because they are hot so more collisions take place.

Increasing Concentration

* There are fewer particles so fewer reactions will take place.

* There are more particles so more reactions will take place.

Increasing Surface Area

* There is not much surface area for the one reactant to react with so fewer reactions will take place.

* There is much more surface area so the one particle has got more to react with so more reactions will take place.

Equipment

Safety Goggles

Conical Flask

Gas Syringe

Weighing Scales

Measuring Cylinder

Clamp Stand

Spatula

Stop Clock

Hydrochloric Acid

Calcium Carbonate - Large

Medium

Small

Powder

Method

. Put 2g of Calcium Carbonate into a Conical Flask.

2. Add 20cm² of Hydrochloric Acid.

3. Put in the Gas Syringe bung.

4. Start the Stop Clock.

5. Stop the stop clock when the Gas Syringe has got to 40cm³.

6. Repeat this twice for each size of Calcium Carbonate.

7. Write the results down in the results table.

Results

Size

st Reading

2nd Reading

Average Time

Large

37.56

30.34

33.95

Medium

82.28

73.29

77.79

Small

33.09

21.43

27.26

Powder

2.15

.87

2.01

Conclusion

As I predicted in my prediction the calcium carbonate with the largest surface area would react the quickest and this was the calcium carbonate powder. The graph shows this information clearly. I took two readings as well to make sure that the results were reliable.

Evaluation

I carried out some good research about the rates of reaction and speeding them up. To make sure that there was a fair test I measured out the hydrochloric acid carefully and weighed out the calcium carbonate. Also I used the same equipment to make sure there was no difference. I could have made the experiment better by using five variables and taking three readings and then taking an average. My method was good and the experiment was set up well. I used safety goggles to make sure that it was safe for me.

By Steven Holt