# Rate of Reaction Between Calcium Carbonate and Hydrochloric Acid

Rate of Reaction between Calcium Carbonate and Hydrochloric acid

The Problem

To investigate how changing the concentration of acid effects the rate of reaction between calcium carbonate and hydrochloric acid.

Background Knowledge

Symbol equation

CaCO3 + 2 HCl --> CaCl2 + CO2 + H2O

Observations

* Fizzing and bubbling.

* The white solid disappears to give a colourless solution

* Container heats up

Rate of reaction

Rate of reaction is the speed at which a reaction occurs, it can be found by recording the amount of reactants used up or the amount of product formed in a given time.

For example in the reaction between hydrochloric acid and sodium thiosulphate a fine yellow precipitate of sulphur is produced. The rate of reaction can be measured as follows.

. A cross is marked on a piece of paper.

2. A beaker with a volume of sodium thiosulpate is placed on the cross.

3. Dilute hydrochloric acid is added and a stopwatch is started and the time taken for the cross to be no longer visible from above.

Over time the cross begins to fade.

For the reaction in this investigation there are a few ways of measuring the rate of reaction. The mass of the reacting mixture would decrease so it could be measured at intervals. But the best way to record the rate of reaction is to measure the amount of carbon dioxide given off using either a syringe or inverted burette underwater.

Collision Theory

The collision theory tells us that for a chemical reaction to take place the two particles reacting must first collide and collide with enough energy to react.

Factors affecting the rate of reaction

HEAT

As the temperature increases so does the rate at which a reaction occurs. As the reacting mixture heats up the particles gain more energy and they move faster, because they move faster there is a greater chance of a collision occurring and when it does occur it is more likely to be a successful collision as the ...