Titration

Titration

Titration is a laboratory technique by which we can use to determine

the concentration of an unknown solution using a standard

concentration of another solution that chemically reacts with the

unknown. This standard solution is referred to as the "titrant". We

have to have some way to determine when the reaction is complete so

you add indicator to the unknown so you can see when the reaction is

complete. This is referred to as the "end point" or more technically

the equivalence point. At that point all the unknown has been reacted

with the standard titrant and some kind of chemical indicator must let

us know when that point has been arrived at.

To find the morality of the unknown you use this formula;

Where m is the morality

V is the volume in dm-3 n is number of moles reacting

Which can be rearranged to find the concentration of the unknown;

Generally we know the morality of the titrant since it is a standard

solution. We also pre-measure the volume of the unknown. We then

titrate with the standard from a burette into the container with the

measured unknown and the chemical indicator until the indicator either

turns colour or a precipitate indicates that the end point or the

equivalence point has been reached. Having the initial and final

readings of the titrant burette gives us the volume of the titrant

used. The only unknown in the above equation is the Normality of the

unknown.

Making the standard solution of sodium hydroxide

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Theory

A standard solution is one whose concentration is known precisely.

These are important because they can be used to find the concentration

of other solutions by titration. It is very important to be able to

make a reliable standard because if the standard is wrong no matter

how carefully you carry out your titration your results will be wrong.

Method

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1. work out how much sodium hydroxide is needed.

2.