Calamine Investigation

Introduction.

Calamine is a mineral containing Zinc Carbonate (Zn CO ). On heating it decomposes as follows:

ZnCO -------ZnO+ CO

(C= 12, O= 16, Zn= 65)

The equation allows you to calculate a theoretical conversion of calamine into zinc oxide. In the chemical industry they need to be able to calculate % yields in order to make sure that their processes are economical.

Aim.

I am going to compare the results from the experiment with the theoretical result to see if they have any similarities or differences.

I have already been told how to find out the theoretical result by using balanced equations and reacting masses.

Prediction.

I predict that the experimental yield won’t be the same as the theoretical yield.

This is because the experiments weren’t as accurate as they could have been. My measurements of zinc carbonate weren’t as accurate as they needed to be, to ensure a fair test. This was because it is almost impossible to weigh exact measurements on electronic scales.

Another problem was there could have been moisture inside of the test tube, which could have affected the results. Even with these problems I think the results will be quite similar to the theoretical yield.

I choose to change the amount of zinc carbonate I used, because I can easily see from these results whether there are any similarities between the theoretical yield and the experimental yield.

Fair Testing.

I will heat the tubes, which contain more zinc carbonate for longer to ensure that the tests were fair. I will also use the same electronic scales for all ...

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I choose to change the amount of zinc carbonate I used, because I can easily see from these results whether there are any similarities between the theoretical yield and the experimental yield.

Fair Testing.

I will heat the tubes, which contain more zinc carbonate for longer to ensure that the tests were fair. I will also use the same electronic scales for all of my experiments, as this will ensure that the tests are fair. I will also were safety goggles to protect my eyes. When I have finished the experiment I will check to see if there were any anomalies, and if there any I will change them, provided if I have enough time.

Method.

1.I will set up all the equipment.

2. I’m am going to do five experiments. I will start with 1 gram of zinc carbonate and heat it up so it loses all of the oxygen that it contains.

3.Then I will find out how much weight it has lost.

4.Then I will do the exact same thing with two grams and record how much weight it loses.

5.I will then repeat this for 3, 4, 5 grams. I will do these five and then repeat the five three times. So I will do 15 experiments in total.

Equipment.

15 test tubes

Stand

Clamp

Bunsen burner

Electronic scales

Spatula

Heat mat

Safety goggles

Tongs

Results:

Experiment 1

Experiment 2

Experiment 3

Average

Conclusion.

My results show that the theoretical and experimental yield is connected in some way. My graph shows that although the experimental results and the theoretical results aren’t the same, they are very alike. This was probably because there may have been moisture retained inside the tube and the accuracy of the measurements weren’t ideal. My results show that my predictions were correct because the experimental results and the theoretical results were very similar and my graph backs this up. On the graph, the experimental results are only a few grams different to the theoretical result and the two lines are very close together.

Evaluation.

The parts of my experiment that gave poor results were the weighing of the zinc carbonate and the moisture within the test tube. There appear to be no anomalies, as all the results were as close to the line as I expected. The result that was furthest away from the line was the 2 gram one, and even this wasn’t an odd result. The results I got were clear enough to form a conclusion because they were as close to the line as I expected and there weren’t any real problems with the experiment.

To improve the experiment, I would have to check test tubes for any moisture, as this was a key factor as to what may have possibly gone wrong with the experiment. I would also have to measure out the zinc carbonate with more accuracy because this is another factor within the experiment to make it variable.

If I was to repeat the experiment I would give myself a lot more time to measure because in this experiment we ran very close to the end of the time we had. Also I would measure the zinc carbonate with more accuracy.