Investigating the factors that affect the rate of reaction between Calcium Carbonate and Acid

Fair Test

For my experiment to be a fair test I am going to make sure that the following factors are kept the same:

* I am going to use Calcium Carbonate in a powder form, as it is far more accurate to measure out so the test will be more accurate.

* I am going to increase the amount of Calcium Carbonate by 2 grams each time I repeat the experiment.

* I am going to use 50ml of Hydrochloric Acid in each experiment.

* I am going to repeat the experiment twice to make sure that the results I get are accurate and to get the average.

* Keep the acid concentration the same.

* The variable in my experiment will be the Calcium Carbonate.

Apparatus

* Conical Flask

* Delivery Tube

* Calcium Carbonate powder

* Hydrochloric acid

* Measuring Cylinder

* Water bath

Diagram

Trial Run

I am going to do a trial run to ensure that the amounts of substances etc. are the most appropriate to use.

I am going to use the trial run to make sure the equipment I am planning to use is appropriate to the experiment I am doing.

Safety

It is important when doing an experiment that I take precautions to make the experiment safer to do. Following simple safety rules will keep the group and myself in a safer working environment. I am going to take the following safety precautions;

. Wear Goggles when doing the experiment.

2. Wipe up any spills on the work surface or floor.

3. Check that all equipment is in a safe position to do the experiment i.e. In the middle of the desk NOT on the edge.

4. Report any glass breakage.

5. Don't run when carrying equipment.

6. Wipe any acid off skin IMMEDIATLEY!

Method

. I am going to add 0.25 grams of Calcium Carbonate powder to a conical flask.

2. I am then going to add 50ml of Hydrochloric acid.

3. I will then measure the amount of gas given off after 1 minute.

4. I will then repeat the experiment with different amounts of Calcium carbonate powder.

5. I am then going to repeat steps 1 - 4 twice to make sure my results are accurate and I am going to use the two sets of results to collect the average result.

Measuring and Recording

I am going to record the amount of Carbon Dioxide gas given off at the end of the experiment. I am going to do the experiment twice to collect an average. I will then plot a graph using the average of the two sets of results from the experiment.

I will also be measuring;

* The mass of Calcium Carbonate powder for each stage of the experiment.

* The amount of Hydrochloric acid used in each experiment (50ml)

* The amount of gas collected in 1 mins (time)

Results

Experiment 1

Mass (g)

0.25

0.5

0.75

.25

Amount of gas given off

(ml)

50

70

10

200

250

Experiment 2

Mass (g)

0.25

0.5

0.75

.25

Amount of gas given off

(ml)

55

90

15

60

260

Average of Experiments 1 + 2

Mass (g)

0.25

0.5

0.75

.25

Amount of gas given off

(ml)

52.2

80

12.5

80

255

Conclusion

From my results table and graph I can see that as I increased the mass of Calcium Carbonate powder the amount of gas collected also increased.

The amount of gas given off can be explained using the collision theory, which means that amount of gas collected went up because, there are more atoms of Calcium Carbonate so the collisions between Calcium Carbonate atoms and Hydrochloric Acid atoms became more frequent because there were more Calcium Carbonate atoms which in turn produces more gas at the end of the experiment.

I have learned that if I increase the mass of the Calcium Carbonate powder but keep the amount and concentration of acid the same the more gas is given off.

The prediction that I made before the experiment was correct according to the results I collected and the graph that I drew.

Evaluation

I think that the method that I chose was a fairly simple but a good and easy method to follow.

If I had the chance to do the experiment again I think I would keep the amounts of Calcium Carbonate powder and Hydrochloric Acid the same but I think I would time how long it took for a certain amount of gas to be collected. I would do this because it would be easier to see the rate of reaction. I would have also used a gas syringe to measure accurately the amount of gas given off.

I think that the results that I collected were fairly accurate but they could be more accurate if I used a measuring cylinder with a smaller scale and used axis with a smaller scale to draw my graph. I could also have used a measuring cylinder with a smaller scale to make sure the amount of Hydrochloric Acid was accurate.

I think I collected a sufficient amount of results to draw an accurate and definite conclusion at the end of experiment as I did the experiment twice to ensure I had enough results and that it backed up my conclusion accurately.

I can tell from my graph that a couple of my results were anomalous, and it could be for the following reasons;

* The amount of Acid or Calcium Carbonate could have been measured inaccurately.

* There could have been some contamination if the Conical Flask wasn't rinsed out properly from the last part of the experiment.

* Some of the gas could have escaped.

* The apparatus wasn't set up properly (e.g. The measuring tube had gas in because it wasn't completely filled with water or water was spilled out of it).

There are several more experiments that could be done to find out the best way to speed up a chemical reaction such as;

* Heat up the Acid to a variety of different temperatures before adding the Calcium Carbonate.

* Use different sized pieces of Calcium Carbonate to put it in the acid.

* Use a variety of Acid Strengths to pour onto the Calcium Carbonate.

* Measure the amount of gas given off over a certain amount of time.