Reactions between HCL and Marble chips

Planning I have decided to investigate the effect of different concentrations of hydrochloric acid on marble chips. I want to see how long it takes for 30cm of carbon dioxide to be given off once the acid and marble chips start reacting. I carried out a preliminary experiment to see what sort of time ranges I was going to expect because I wanted to get the concentration levels right otherwise I could have been waiting …

…the lower concentration not heating up the reactants is true or not. For further investigation I could use stronger acid to see if there is limit to how quickly the reaction can take place. Also, I could measure the mass loss of the reaction by having the conical flask on a top pan balance. I could take away the mass at regular intervals from the original and find out how quickly the reaction takes place.