This experiment is to see how fast metal carbonates will break down to produce carbon dioxide.
The reason they break don’t break down at the same time is because more reactive ones don’t want to break up. So the longer it holds onto its carbonate the more reactive the metal is.
In this experiment there are a few factors that can affect the results of the experiment. These factors can make the results of the experiment be incorrect. The factors that can affect the experiment are:
- Water
- Amounts of powder
- Distance the flame is away from the metal carbonate
Water can affect the results because it can get into the powder, which can speed up a reaction.
If different amounts of the substance are used, then the results can be affected because the more amount of powder there is, the more carbon dioxide will be produced.
Plan
In this experiment I plan to use 1/500 of a mole. This is because if anything greater is used then the amount is too great and the results would be high, so if a 1/500 of a mole is used the results will be good enough to get a decent result form that won’t be too high.
This is how I worked out how much to use:
1 mole of Co2 occupies
22.4 litres
50
Which is equal to 1/500
My plan is to use 1 mole of metal carbonate, as it will be sufficient enough for what I will be using it for. This investigation tests the rate of reaction of different metal carbonates. This is how my investigation will be set up:
Diagram
Apparatus
- Gas syringe measured in millilitres (ml)
- Stop Clock
- A set of scales weighed in grams (g)
- Zinc, magnesium, copper, calcium and chorine metal carbonate (1 mole)
- 5 test tubes
- Delivery tube
- Bunsen burner
- Heat proof mat
- Clamp
- Ruler
My apparatus was set up as in the diagram. In this experiment one mole of each metal carbonate was placed in the test tube then a cork was placed on the top, which secured the tube from the syringe in place. Once this was done the syringe would be set to 0 so that the results that we ended up with were true to the experiment. The metal carbonate was then heated and the CO2 levels were recorded. After each experiment a change in apparatus was needed so that a fair set of results could be recorded.
In this experiment all factors will stay the same, apart from the metal carbonate. The mass of the metal carbonate will remain constant (1 mole of the metal carbonate). The reason why one factor is changed in the experiment is so that a fair set of results can be taken. Each metal carbonate will be tested 3 times so that an average can be taken. The mass of the metal carbonate will remain constant through out all the experiments; the distance that the metal carbonate will be away from the flame will be the same.
Prediction
In this experiment I expect that that the metal carbonates that are higher up in the reactivity series will produce more carbon dioxide. I believe this because of my research into the background of reactions. This is the order of the reactivity series:
I predict that the looser the bond of the metal carbonates the quicker it will react and produce Co2. The more reactive the substance the stronger the bond will become. I expect from my experiment that the most reactive metal will hold out the carbonate most strongly.
This is my pattern statement:
Metal carbonate + heat --> Carbon dioxide
This is what I think the equations to the experiment will be:
-
Na2CO --> Na2 + CO2
-
CaCO3 --> CaO + CO2
-
MgCO3 --> MgO + CO2
-
ZnCO3 --> ZnO + CO2
-
CuCO3 --> CuO + CO2
Results table
Analysing
From my graph and my results I can see that the magnesium carbonate produced the most carbon dioxide gas, and calcium carbonate produce the least amount of gas. This is the pattern statement that I got from my graph, ‘the stronger the bond the harder I is to break when burnt’.
Evaluating
When I was actually doing the experiment I tried to keep all but one factor the same. The factor that I changed was the different metal carbonate. Each time I tested each metal carbonate three times and then moved on to another one. From my graph there are many anomalous results. Three things can cause these:
- Water
- Amount of metal carbonate
- Distance the flame is away from the metal carbonate
If water gets into the carbonates then it will affect the results making them incorrect. Drying out the carbonates prior to the experiment so this isn’t a factor can prevent this. Maintaining the same temperature throughout all the metal carbonates is crucial so that the experiment is fair. A ruler can be used to measure how far it is away from the flame so that the temperature is kept roughly the same all he way through the experiment. My results are not reliable because from my graph there are a lot of anomalous results that indicates something went wrong in the experiment. I think that the reason why the results were how they were was because