describe the set-up for a buret.?

Answer 1

If you mean how to set up a burette you collect the acid in a labelled beaker and a substance to neutralise in a second labelled beaker. Also a conical flask and some indicator such as universal indicator or methyl orange. Put the burette in the clamp and put a small amount of acid in. Then pour it out of the open end slowly whilst revolving the burette. This helps to minimise contamination. Also allow a small amount of acid to run through the tap. Then fill the burette with acid up to 0, the meniscus should be at 0. Then whilst swilling the solution to be neutralised in a conical flask mix the solutions. Then record how much acid has been used to neutralise the solution. This is called the titre. The first one should be rough, then secondly allow the acid to run fast but slow down as you reach the area where it changed before. Then add the acid drop by drop.
This means that providing you have the same amount of solution to be neutralised and of the same concentration, it should always take that same amount of titre to neutralise with the same concentration of acid. This can be done precisely and shouldn't require indicator. By recording the amounts of solutions and concentrations you can work out the concentration of volume of the other reagent.