When a metal is extracted from its ore often sulphur dioxide is produced. When sulphur dioxide is dissolved in water it forms a strong acid called sulphuric acid. Sulphuric acid is often sold as a useful by-product, but also gets into the water cycle and forms acid rain. In this experiment, I have been given a sample acid rain of concentration between 0.05 mol dm-3 and 0.15 mol dm-3 and my aim is to find out exactly what its concentration is. To do this I have been given solid anhydrous sodium carbonate and a range of pH indicators. With this solid anhydrous sodium carbonate I can make a solution of known concentration by mixing it with distilled water to make sodium carbonate solution (which is an alkali solution). Once I have mixed this solution I can use it to perform a series of titrations to find out accurately what the concentration of the acid rain is. I have chosen to perform a titration because it is an accurate method of finding out the unknown concentration of the acid rain and titrations can be executed completely by using standard lab equipment. Neutralisation Reaction
A reaction between solutions of acids and alkalis that give neutral pH products are known as neutralising reactions. In this experiment I know the concentration of the alkali (sodium carbonate) and I shall use this knowledge to find out the roughly known concentration of the acid (sulphuric acid).  When an indicator is mixed with the acid the solution will turn to a colour. When enough sodium carbonate is added to the coloured solution it will turn to another colour. This is called the end point and it means the solution is neutral. In a titration this process is used to find out the concentration of a solution by mixing it with a solution with known concentration. Acid Rain
The term "acid rain" is commonly used to mean the deposition of acidic components in rain. Distilled water, which contains no carbon...