Rate of Reaction Between Marble Chips and Dilute Hydrochloric Acid

An investigation into how changing one variable influences the rate of reaction between marble chips and dilute Hydrochloric acid

Planning Section

When dilute hydrochloric acid reacts with marble chips the following reactions occurs:

CaCO3 + 2HCL = H2O + CO2

This is the reaction we will be investigating. We will be investigating what changes the rate of reaction.

A list of variables that could affect the rate of reaction

- Temperature

- Concentration

- Surface Area

- Temperature: This variable changes the rate of reaction, when the temperature is increased the rate of reaction is quicker, because the particles have more energy to move around and collide with each other.

The more collisions between particles in a given time, the faster the rate of reaction.

- Concentration: There will be a concentration of acid and a concentration of water as well. This variable changes the rate of reaction, by adding more acid in concentration than the water then the reaction will take place quicker because there is more acid to react with the marble chips, and if you add more water then the reaction will take longer because there is less acid to react with the marble chips. - Surface Area: this variable changes the rate of reaction because if we increase the surface area, we increase the rate. Surface area is the measure of how much surface is exposed. So for the same mass of the marble chips, small chips have a larger surface area than bigger chips, this means that rate of the small chips will be quicker than the bigger ones.

Here are reasons why changing the variable is likely to have an effect: - Temperature: if you are to change the temperature it will change the rate as well. If you increase the temperature this will increase the rate, because the heat gives energy to the acid and water particles, which means they hit the marble chips more.

- Concentration: If you are to change the concentration there is a definite change in the rate. The more acid you add the quicker the rate because as you increase the concentration of the acid, there are more acid particles in the same volume. Therefore there is greater chance of acid particles hitting and colliding, with particles on the surface of the marble. You have increased the rate of reaction.

- Suface Area: if you are to change the surface area it is going to affect the rate. The larger the surface are then the rate will be quick, the smaller the surface area the slower the rate. The more the collisions between particles in a given surface area the quicker the