Investigate the effect of increasing concentration of hydrochloric acid on the rate of reaction in the reaction between hydrochloric acid and marble chips.
Description
(experiment introduction “should be paraphrased”)
Marble is a metamorphic rock composed of calcium carbonate. Hydrochloric acid reacts with calcium carbonate to form calcium chloride, water and carbon dioxide.
The equation is:
CaCO3 + 2HCl CaCl2 + H2O + CO2
The rate at which carbon dioxide is produced provides a method of measuring the rate of reaction. The most convenient way of doing this is by following the loss in mass as the gas is evolved, because carbon dioxide is sufficiently dense to cause measurable decreases in mass using a standard laboratory balance.
You could carry out a preliminary experiment by adding hydrochloric acid to some marble chips and show that the gas evolved is carbon dioxide by its reaction with limewater.
