Plan:
We are investigating the effect of nitric acid on calcium carbonate. We are doing this experiment, as we would like to understand the effect that acid rain has on limestone. We also want to understand how acid can have an effect on rate of reaction.
The word equation for the reaction that will take place is:
Calcium Carbonate + Nitric Acid Calcium Nitrate + Carbon Dioxide + Water
The balanced symbol equation is:
CaCO3 + 2HNO3 Ca(NO3)2 + CO2 + H2O
In the experiment we could change: (Independent Variable) - The concentration of the acid - The temperature of the acid - Surface area of the calcium carbonate - The amount of acid - The amount of calcium carbonate - Add a catalyst to the reaction All of these have an effect on rate of reaction however, the independent variable that I will choose will be the concentration of the acid. I will use five different concentrations and I will test each concentration three times. This way my results will be reliable as the tests have been repeated.
Concentration Table:
Concentration
Volume of acid
Volume of water
100%
50cm3
0cm3
80%
40cm3
10cm3
60%
30cm3
20cm3
40%
20cm3
30cm3
20%
10cm3
40cm3
In the experiment I will use: - 50cm3 of nitric acid solution - 2 grams of calcium carbonate - Small chips of calcium carbonate These will be my control variables. I will keep; the amount of acid; the amount of calcium carbonate; the surface of calcium carbonate and the temperature of the acid the same. I will also not add a catalyst to the solution. Apart from the concentration of the acid; I am keeping everything else the same in order to have a fair test. I will also wash out the conical flask and measure my solutions carefully. I will do this to ensure that my results are accurate.
In the experiment we could measure: (Dependent Variable) - The volume of gas produced in a