After performing a titration, how do you calculate the esimated error in a titre?

Question

I'm doing a degree in chemistry. After working out the concentration of an acid I was asked to include the error as well but I don't know a simple way to calculate it.

Answer 1

You need to know the error on

1. The burette
2. The pipette you used to dispense the titrand
3. The volumetric flasks the titrant and titrand were made up in
4. The pipette used to dispense the conc. acid prior to making up your titrant solution
5. The balance used to weigh out your primary standard prior to making up your titrand solution

Most errors are summative, so you should be able to just add them all up!

Most glassware is type B, but if you have used type A then remember that the errors quoted are only valid as long as the type A glassware has not been oven dried...otherwise it reverts to type B error specification. Values for glassware error (sometimes called tolerance) are available on the web. Remember to quote your source if you use those values.

Answer 2

You need to look at how accurate the burettes, pipettes or measuring cylinders you used are. A lot of them you will find it printed on like '20ml +- 0.1ml at 25C' so a 0.5% error (can't do the right symbols on here the minus sign should be under the plus). Look at all the different potential errors you have. You may need to add them all up depending on the equipment you were using.