Titration recording results

Okay so my A2 isa is coming up soon and I know it's a titration. I know I should really know this by now but I have no clue how you're actually supposed to record your results. Practicals are really not my thing.

So you're meant to do a rough reading and then approx 3 more. The other readings should be 'Initial volume', 'Final volume' and 'Titre' but what does this actually mean? I always just used to refill my burette up to 0 after each titre but I think that's not what you do...

Can someone explain how you actually do your results table and what to put under each heading?

Hey there !

Titrations are pretty simple as long as you follow a few simple rules.

So, fill your burette to somewhere close to zero. Dont worry about getting it exactly at zero... It doesnt really matter.

Now, open the burette tap and let some liquid flow through... You're basically trying to expel any air bubbles in the nozzle region as well as flood the section just above the tap.

Record the liquid volume in the burette as your INITIAL VOLUME. Usually, you look at the lower meniscus for this. This may depend on the chemical used.

Now do a rough addition... Just run through your chemical in the burette at a steady yet pretty fast rate whilst swirling your conical flask heavily. Watch for a colour change, close the tap and record the FINAL VOLUME in the burette.

^This is your 'rough' addition.

FINAL VOLUME - INITIAL VOLUME = Titre. Always note, your volumes will always be to 1 d.p. (at least during your A levels but best check the scale on the burette) .

Repeat the same process by topping up your burette and recording your initial volume. Feel free to run the chemical through the burette quickly till within a few ml of your rough end point and then slow it down to a drop by drop process.

Remember, constant swirling is important.

In the end, aim for at least 2/3 proper titrations and 1 rough titration.

NOTE : When using a pipette to measure and transfer chemicals always make sure you have no air bubbles... This can throw off your experiment.

Have fun and feel free to ask more questions

Thank you so much. So do you not need to re-fill your burette every time? Can you just use your final volume from the first titration as your next 'initial reading?' (if that makes sense)

I know what you mean but there is a danger that you may not have enough for the next titration. However, that's a judgement you need to make on the day and will depend on the reaction being done.

Its your call and should be pretty obvious which way you should go

Another tip : you usually load your burette using a filter funnel. REMOVE the filter funnel before starting the actual titration. Do not keep it on.... Residual liquid in the funnel may enter the burette and hence you'll land up underestimating the volume added.