Planning Aim I aim to investigate how temperature affects the rate of the reaction of Calcium carbonate and Hydrochloric acid. I have established that:- Calcium carbonate + Hydrochloric acid = Calcium chloride + Carbon dioxide +water This equation can also be stated using symbols :- Ca CO s + 2HCl ag = CaCl ag + H O l +CO Variables A variable is a factor which we can measure or control. There are several variables which I could change and study the effects of there changes. These are the following:- ...
more accurate readings and therefore more reliable results.

Another alternative experiment involves the change in mass being measured every 10 seconds. The Carbon dioxide produced in the reaction escapes into the air. The cotton wool plug is there to stop acid spray from escaping. This method is more reliable because a top-pan balance is more accurate than using a measuring cylinder to take results from. Using a cotton wool plug would also eliminate the problem of leakage of gas at the beginning of the experiment, as the bung allowed.