The Student Room Group
Reply 1
It's hard to tell when the end point is sometimes, and you can get errors on volumes and concentrations as well.
Reply 2
How are you measuring the end point? Colour changes are subject to human error (Just how pink does the solution have to turn etc).

Mention that the burette is accurate to ±0.05cm^3 which is a very minor inaccuracy.
In general titration is an extremely accurate procedure based on the ±0.5cm^3 and the fact that you repeat until you have two or three consecutive results.
Contamination?
Reply 4
All sorts really.

Paralax error (reliability of reading off the burette), untrue concentrations or moles in the volume of acid / alkali used (especially sensitive in the schools equiptment), calibration of the burette (NOT a paralax error), if you're repeating results how well youve cleaned out the burette especially (assumabley with non polarised water).

Question each step and be critical to deduce how these errors may affect your readings on a smaller scale.
End point, contamination if your changing conc./schemicals running through the burette or ,into the conical flask, source of error from burette/pipette/volumetric flask etc

To help, use white tile to see end point easily, clean out equipment fully/ reord source of error and work out total % error in evaluation etc
Reply 6
- If you're making up your one of your solutions to use in the titration you may not transfer all of the solid/dissolve it properly.
- Misreading the level on the burette/volumetric flask/measuring cyclinder
Stephens
All sorts really.

Paralax error (reliability of reading off the burette), untrue concentrations or moles in the volume of acid / alkali used (especially sensitive in the schools equiptment), calibration of the burette (NOT a paralax error), if you're repeating results how well youve cleaned out the burette especially (assumabley with non polarised water).

Question each step and be critical to deduce how these errors may affect your readings on a smaller scale.

(Emphasis mine)

Deionised, surely?
Reply 8
Revd. Mike
(Emphasis mine)

Deionised, surely?


Deionised, non polarised, same thing.
Not really. An H2O molecule is polarised, and you're not going to change that!

Latest