When you have done this with the first concentration of acid clean out the conicle flask and refill the measuring cylinder & repeat experiment with next concentration of acid.
Equipment
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Water
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Conicle Flask
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Bung
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Marble chips
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Water Basin
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Tube
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Acid amounts (0.25M, 0.5M, 1.0M, 1.5M, 2.0M)
- Timer
Vairiables
Concentration of acid -> higher the concentration faster the reaction
Mass of limestone - (Which is not changed other than test specs)
Surface area of limestone - Greater the surface area -> faster rate of reaction
Temperature - Increasing the temp -> increases the reaction rate
Theory
The concentration of acid has a major effect on the results. For our experiment we used 25ml of acid (All of the concentrations used the same amount) 0.25M, 0.5M, 1.0M, 1.5M, 2.0M. 'M' Means molar which is how the strength of acid is measured.
The stronger the concentration of acid used will effect the amount of gas produced, the more acid used - the more gas created & visa versa.
Prediction
I predict the more gas made will be dependent on how much acid is added.
Safety
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Use goggle eye protection
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Rinse acid contacted area with water & seek help
Results
Experiment 1
Experiment 2
Averages Table
Conclusion
My results have shown that when i use a stronger acid the rate of reaction between calcium carbonate and hydrochloric acid increases because, there is more contact between particles of acid and particles of calcium carbonate. There is a definate partern to both my graphs and results and this is that the stronger the acid the quicker carbon dioxide was produced. This is shown of the graphs by a steadily increasing line. This proves my prediction to be correct, because I predicted that a stronger acid would give more carbon dioxide quicker than a weaker acid and this was true. 2.0M acid was so fast compared to 0.5M acid because in 2.0M acid there is a higher concentration of particles of acid so there is more chance of a collision between acid particles and calcium carbonate particles. In 0.5M acid it was so slow because there is a quater of the amount of acid particles in 2.0M acid. I can draw a labelled diagram which shows particles of acid colliding with marble chips and making gas and I can use this to explain what I found out in my results.
Evaluation
I cannot think of a better way of doing the experiment or collecting more accurate results except than using more detailed measuring cylinder's. I do think that taking averages helps because it gives an average result which means that it can be more accurate than lots of individual results. The main difficulties in doing this experiment I think were taking results accurately.