The Affect of Changing the Concentration on the Rate of Reaction

The Affect of Changing the Concentration on the Rate of Reaction

To find out the affect of changing the concentration on the rate

of reaction

Scientific background

Collision theory: Collision theory explains how chemical reactions

occur and why rates of reaction differ. For a reaction to occur,

particles must collide. If the collision causes a chemical change it

is referred to as a fruitful collision and it's a Theory that explains

how chemical reactions take place and why rates of reaction change?

For a reaction to occur the reactant particles must collide. Only a

certain fraction of the total collisions cause chemical change these

are called fruitful collisions. The fruitful collisions have enough

energy (activation energy) at the moment of impact to break the

existing bonds and form new bonds, resulting in the products of the

reaction. Increasing the concentration of the reactants and raising

the temperature bring about more collisions and therefore more

fruitful collisions, increasing the rate of reaction.

Rate of reaction: amount of a substance that takes part in a chemical

reaction in a given time, and its also Finding out how quickly

reactions take place and understanding why they happen at the rate

they did.

Molecules: Molecules are compounds made up of atoms.

Movement: is how the reaction occurs

Activation Energy: the minimum energy in the reaction.

Prediction: What I predict to happen in my experiment is that when I

add 10 cm3 of Hydrochloric acid into the flask with the sodium

Thiosulphate of 50cm3 then I hypothesise that the cross will disappear

a lot faster than when I add less amount of Hydrochloric acid.

Hypothesis: I predict is that when I use high concentration of Na2S2o3

the rate of reaction would be very fast and the cross is going to

disappear more rapidly and when the solution is more diluted by adding

more (water) so the reaction will slow down much slower and it will

take more time for the cross to disappear. I think this will happen

because by adding more water in it will produce more particles in the

concentrated solution so because of this there will be more collisions

and it will slow down the reaction.

Apparatus: In order to do any type of experiment, you need equipment.

The equipment I will use is:

Measuring Cylinder

Small measuring cylinder

Flask

2 beakers

Paper marked with a big cross in the middle.

Stops watch (Timer).

Method:

- Firstly we got the equipments listed above

- Then we set it up the equipment as shown above.

- We got a piece of paper and drew a big cross on it.

- Then using a conical flask and 100ml beakers and a 250ml beaker we