To investigate the factors affecting the rate of reaction of calcium carbonate (limestone) with hydrochloric acid

FACTORS: The things that could change, that would affect the rate of reaction are:

Surface area- crush limestone

The strength of acid- moles

The mass of limestone

The temperature of the acid

The amount of acid used

Adding a catalyst

Pressure

VARIABLE: I am going to change the heat of the acid. I will heat it first at 30C, then 40C, 50C, 60C and then 70C.

EQUIPMENT: Measuring cylinder, Bunsen burner, Boiling tube, 3 grams of limestone chips, Rubber bung, Stopwatch, Beaker, Conical flask, Thermometer, Gauze, 25mls of hydrochloric acid {1.5 molar}, Water bath, Delivery tube, Tripod and a heatproof mat.

DIAGRAM:

METHOD:

) Place the Bunsen burner under the tripod on the heatproof mat, on top of the tripod place the gauze.

2) Fill up beaker with 100mls of water, put the beaker on top of the gauze.

3) Heat the water up until it reaches 30C.

4) Pour 25mls of the 1.5 molar hydrochloric acid into the boiling tube.

5) Place the boiling tube in the beaker and put the thermometer in the boiling tube to make sure the acid is at 30C.

6) Fill the measuring cylinder up with water.

7) Turn the water bath, upside down over the cylinder and hold the bath down firmly.

8) Tip the bath and cylinder upside down, still holding them together firmly so that the bath is placed firmly on a flat surface with the cylinder inside it. Hold the cylinder tightly in the bath to make sure no water escapes.

9) Weigh 3 grams of limestone chips and put them in the flask.

0) Pour the acid into the flask, quickly put the bung on the flask inside the bung there is a delivery tube, put the other end of the tube under the cylinder in the bath.

1) As soon as the acid touches the limestone, then start the stopwatch and stop at 30 seconds.

2) When 30 seconds are up, look at the flask and record the level of the water.

3) Repeat the experiment 2 more times.

FAIR TEST: To keep this a fair test, I will keep everything the same but I will change the temperature. I will not change the set up.

SAFETY: To carry out this experiment safely, I will wear safety glasses all the time so that the acid or flames can't contact my eyes. I will be careful when handling the acid as it can be harmful to the skin and I will not sit down whilst doing the experiment.

RESULTS:

Temperature

Test 1

Test 2

Test 3

Average rate of reaction

30 C

57ml/30secs

50ml/30secs

40ml/30secs

49ml/30secs

40 C

65ml/30secs

65ml/30secs

50ml/30secs

60ml/30secs

50 C

80ml/30secs

70ml/30secs

69ml/30secs

73ml/30secs

60C

00ml/30secs

97ml/30secs

91ml/30secs

96ml/30secs

70 C

30ml/30secs

27ml/30secs

99ml/30secs

19ml/30secs

CONCLUSION: Like I said in my prediction as the temperature increased, so did the rate of reaction also as it says in my scientific knowledge the collision statement did take place. As the temperature became more the particles began to move faster which resulted in more collisions.

EVALUATION: After evaluating my results they were not very useful, I repeated the method three times then I could find the difference between the results to work out the average, if I did this experiment again I think the equipment would have to be different. I could also change the amount of acid and limestone or even the temperature.