The higher the temperature of the sodium thiosulphate the faster the

The higher the temperature of the sodium thiosulphate the faster the

reaction of the two liquids.

Information.

According to the kinetic theory all matter is made up of tiny,

invisible particles that move all the time. When the temperature is

increased around or on these particles, the faster they move. Heavier

particles move more slowly than light ones at a given temperature.

This theory defines the differences between solids liquids and gasses;

in a gas the particles move freely and at random in all the space

available, in solids particles only vibrate around fixed positions and

in liquids the particles have some freedom and can move around each

other. Using the kinetic theory we can explain changes in the state of

substances as they are heated and cooled. We can also explain

dissolving and diffusion using the kinetic theory. The kinetic theory

says that gases diffuse to fill up the space around them. This

explains how the smell of cooking can be smelt all over the house

after a short period of time. It's not only gases that diffuse,

diffusion occurs in liquids too. Diffusion involves the movement of

particles from a region of higher concentration towards a region of

lower concentration. The kinetic theory can be used to explain the

factors affecting the rates of reaction, this is an extension to the

kinetic theory called the collision theory. The collision theory says

that Chemical reactions occur when particles of the reactants collide.

They must collide with a certain minimum energy, called the activation

energy.

To summarise, the requirements for an effective collision (for a

chemical reaction to occur): The reactants must collide with each

other, The molecules must have sufficient energy to initiate the

reaction (called activation energy).

Planning

This experiment is to discover what affects rate of reaction. In this

experiment there are two solutions used, Sodium Thiosulphate and

Hydrochloric Acid.

(Sodium Thiosulphate + Hydrochloric Acid) (Na2S2O3 (aq) + 2HCl (aq)

In this reaction, a fine precipitate of sulphur slowly forms, to

measure the rate of reaction, we time how long it takes to form the

precipitate. Five of the most common ways to influence the rate of

reaction can be explained using collision theory. They are: changing

the nature of the reactants, changing the concentration of one or more

of the reactants, changing the temperature at which a reaction is

performed, changing the surface area of a solid reactant, adding a

catalyst.

I have chosen to study how the rate of reaction changes when the

temperature of the sodium thiosulphate is varied.

Before we could conduct the experiment there was some preliminary work

to be done. This was to find out what amount of each liquid would be