The higher the temperature of the sodium thiosulphate the faster the :: GCSE Chemistry Coursework Investigation

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