What Affects the Speed of Reaction Between Calcium Carbonate (Marble) + Hydrochloric Acid?

6. Pestle and mortar to crush the calcium carbonate into powder

7. A burette to measure accurately the Hydrochloric Acid

The method I am going to use to perform my experiment are-

. Set up apparatus

2. Measure out 25cm3 of acid using a burette (accurately) 0.1cm3.

3. Weigh out 1g of marble chip to the nearest 0.01g

4. Add marble to acid, put the bung in + measure CO2 gas given off at 30 seconds, record the co2 given off.

5. Repeat twice to check result

6. Repeat with the next 5 concentrations

I am going to use 1.00g of marble chip to make my experiment a fair test. I am also going to repeat my experiment twice more, also for a fair experiment, just incase I make a mistake on my first try!

Safety

must always wear safety glasses and we should be very careful not to drop any acid.

Fair test- we must make sure that we use the same size, amount and

roughly the same mass of chips, this is because we want to keep the chips

roughly the same all the way through the experiment so that it will be a

fair test and the results we be in relation to each other, otherwise the

results will be completely different to what we will expect and it will

ruin the experiment. We must also take our readings at the same intervals

throughout the experiment i.e. I will take a reading every fifteen seconds

for all of my experiments.

I predict that the more concentrated the acid the quicker the

reaction will take place, because the more concentrated the acid is then

it will make the chips react faster and more hydrogen will be given off in

a quicker time. The smaller the stones are, the even quicker the reaction will happen, this is because the acid has a smaller surface area to act upon. Other factors are what kind of water to use for dilution, I could either use water from the tap which is not very pure or it may be too hot or too cold, or I could use distilled water.

Tap water may have some things in it which may affect the results. The temperature also could affect the experiment because if heat is applied then the particles would move around more and affect the results ,and then more gas would be made.

Results

Concentration

Time to get to 20cm3

25, 0

56

20, 5

70

5, 10

02

0, 15

83

5, 20

29

Evaluating Evidence

I think that the experiment went very well. This is because I got all the results that I wanted and they look very good. The results were very accurate and so I am able to make a good conclusion. From looking at my results I can see that there were no poor results which was a good thing and it proves that everything went very well. Even though the experiments went very well I decided to repeat one concentration of acid twice just to see if I could repeat the experiment and get roughly the same results, which is what I did do, and these to went very well. There was no real source of error in the apparatus along as it all was working well and the way it should of been. The only possibility was if the temperature of the acid had changed from when we did the first reading to the finish i.e from when we did the first experiment, the acid hopefully would have been the same temperature.

Analysing Evidence and Conclusions

From looking at my results and graph I am able to conclude that the more concentrated the acid the quicker the reaction happened and the more gas was produced. As we look at the graph we can clearly see that in all five results at the beginning the reaction happened more quickly than at the end where we can see that it started to tail off.

Before I did the experiments I made some predictions they were that the more concentrated the acid was the quicker the reaction would happen and more hydrogen would be produced. This was completely correct because what I thought would happen did.

At this point we are able to answer our main hypothesis which was 'how does changing the concentration of acid affect the rate of reaction between hydrochloric acid and calcium carbonate.' The answer to this would be that changing the concentration of the acid will either make it go slower or quicker and more or less gas would be produced depending on whether the concentrations were more or less.

Overall this was a very successful experiment and everything went very smoothly, and that was why my results were very good, and I am able to make a conclusion like this.