Rates Of reaction- The reaction between limestone and hydrochloric acid

Essay by melissa-whiston April 2006

Aim

During this experiment I will be investigating if heating limestone and changing the concentration of the acid will affect the rate of reaction.

Preliminary work

Before doing our main experiment, we will have to conduct another experiment, to see what concentration of acid we will have to use. We done this using 0.1M, 0.5M and 1M of Hydrochloric acid, and 0.1g of powdered limestone, we used powdered limestone, as it would be a fairer test, I think this as all the particles of limestone will be roughly the same size, the particles have a larger surface area than cubed limestone, therefore it will react the quickest. If you were to use cubed limestone it wouldn't be fair as no cube will be exactly the same size. In conclusion to this experiment, 0.5M of acid was the best to use as it had the best measurable reaction time.

Equipment

The equipment we will be using during this experiment is:

*Goggles (to protect the eyes from reactions)

*Measuring cylinder (to measure out the acid)

*Bunsen burner (to heat the acid to the right temperature)

*Test tubes (to hold first experiment in)

*Hydrochloric acid (the acid being used)

*Powdered limestone (the substance being used)

*Triangular stand (to hold the Bunsen burner)

*Timer (to time the reaction)

*Thermometer (to record the temperature)

Diagram

Possible Variables

The possible variables are:

*Temperature of acid- this will determine how quickly the reaction happens e.g.

the limestone reacts faster or slower under a certain temperature. When the acid is heated, the particles gain

*Amount of Hydrochloric acid used

*Amount of limestone used

*Surface area of limestone- this will determine how quickly the reaction will happen e.g. If the limestone is cubed or powdered

*Concentration of acid- this will determine whether the limestone dissolves faster...