Tips for Titration Practical Test (1 Viewer)

[danz90]

I've got a practical assessment tomorrow based on a titration, with some questions involved also. I have studied alot about volumetric analysis, but I would appreciate any tips for undertaking a titration, particularly in the context of a practical exam.

 

[lil lelu]

your first titrate do very slowly, drop by drop to get where the end point is (change of colour). we always did 3 titrations, so the next two you can pour it in quickly just before your pervious reading. dont get impatient and go too quickly cause only one drop is needed to reach the end point. hope that helps

 

[minijumbuk]

your first titrate do very slowly, drop by drop to get where the end point is (change of colour). we always did 3 titrations, so the next two you can pour it in quickly just before your pervious reading. dont get impatient and go too quickly cause only one drop is needed to reach the end point. hope that helps

I believe it's the opposite. We're meant to do the first titration quickly, hence its name "rough titration". We never take into account the results obtained from the first titration, as we only use it to give an approximate result. Say you just let the biurette run, and it changes colour at around 25 mL, but your reaction time isn't fast enough, because you were just letting it run. In the second/third/fourth/Nth titration, you can now let the biurette run for the first 20 mL, THEN let it drop very slowly, so that you don't have to waste time dripping it for the whole titration.

 

[lil lelu]

I believe it's the opposite. We're meant to do the first titration quickly, hence its name "rough titration". We never take into account the results obtained from the first titration, as we only use it to give an approximate result. Say you just let the biurette run, and it changes colour at around 25 mL, but your reaction time isn't fast enough, because you were just letting it run. In the second/third/fourth/Nth titration, you can now let the biurette run for the first 20 mL, THEN let it drop very slowly, so that you don't have to waste time dripping it for the whole titration.

well thats the way we do it at uni

 

[brenton1987]

well thats the way we do it at uni

You should not be using an indicator at uni. Cant your uni get pH probes?
Differential plots using a pH probe are the way to go. Makes titrations so much easier.

 

[lil lelu]

You should not be using an indicator at uni. Cant your uni get pH probes?
Differential plots using a pH probe are the way to go. Makes titrations so much easier.

nah we used indicator, dont know why.

 

[minijumbuk]

It's not even logical to do it that way, since you could be sitting there all day dripping one drop by another =O

 

[dood08]

It's not even logical to do it that way, since you could be sitting there all day dripping one drop by another =O

.. thats why you do a rough run, failure.

anyway, make sure you add 2-4 drops of indicator, and wait 30 secs after the colour change to ensure that is a permanent. - often it will still discolour.

also it'd be good to learnt the difference between end points and equivalence points

 

[minijumbuk]

...

I'm so sick of people not reading the previous posts before posting.
I was commenting on the "uni method", and they did not mention to do a rough run, failure.

 

[henry08]

Would you really have to do a titration as a prac as titratiosn are grnerally a long experiment.

 

[minijumbuk]

I doubt it, especially if you have a huge grade doing chemistry.

But just in case you do, the teachers will make sure that the titration won't take too long, like having to use like 48 mLs of solutions each time =P

 

[Shadose]

Make sure you keep swirling the conical flask.