The Effect of Concentration on the Rate of Decomposition of Calcium Carbonate.
- Essay length: 2728 words
- Submitted: 11/03/2001
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The Effect of Concentration on the Rate of Decomposition of Calcium Carbonate.
PLAN
I planned my experiment based on the scientific knowledge I already have: If I increase the concentration the rate of reaction increases. This is because the higher the concentration, the more liquid (acid) particles there are in the same volume, to collide and react with the solid (calcium carbonate) particles. Therefore the rate of reaction increases. Basically the probability of the particles colliding and reacting is increased, when the concentration is increased.
E.g.;
Lower concentration Higher concentration
Prediction:
I believe that the rate of reaction will increase with increase in concentration. This is because as explained above. The higher the concentration, the more liquid (acid) particles there are in the same volume, to react with the solid (calcium carbonate) particles. Therefore the rate of reaction increases.
Basically, at higher concentrations, there are more molecules per litre, so there will be more collisions, so the reaction rate should be higher at the same temperature. Doubling the concentration should double the reaction rate. However for some reactions, the rate may be proportional to the concentration squared. For some reactions it can even be proportional to the concentration to the power 1.5
The Kinetic Rate Law defines the relationship between concentration and reaction rates. According to the law, the rate is directly proportional to the molar concentrations of each reactant in the rate-determining step of the reaction mechanism; each raised to a power equal to their rate order. The Rate of a chemical reaction is equal to a rate constant multiplied by the molar concentration of each reactant raised to the power equal to the rate order. For example if we have a chemical process defined in the following manner:
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Continuation
A + B ----> C
According to the Rate Law:
Rate = k [A]m [B]n
where:
k = rate constant
m = rate order in respect to A
n = rate order in respect to B (http://edie.cprost.sfu.ca/~rhlogan)
Preliminary Plan
Measurements I chose:
Size of calcium carbonate: Medium
Concentration values of acid: 50:0
40:10