Titrations

Well, today I did a titration practical test.

I was confident of it, really - simple hydrochloric acid VS standard sodium carbonate. Didn't even have to create a standard.

We got about 100ml of each that was to last us the whole thing.

I pipetted 20mL of sodium carbonate into a conical flask and put methyl orange into it.

I had elected ot have the HCl in my burette so I poured some in to run through and give it a clean. unfortunately, I put about 20mL in, which was disaster right away seeing how I only had 100mL to work with.

So I put a funnel in the top of my burette and tipped the beaker of clear, colourless solution into it. I noticed the burette was only a third full (crap), and asked the teacher if I could have more HCl. he said you have to deal with what you're given, and then I noticed the black pen on my beaker that proclaimed what I had just poured into my HCl-rinsed burette as Na2CO3.

So I had to discard the Na2CO3 in the conical flask and use HCl.

I ended up having to get more Na2CO3, for which 10% has been deducted (d'oh). Did a rough titration and then a more accurate one, and I was setting up to do a second accurate one when, much to my dismay, I was something like 2mL off having the 20mL needed for the pippette to fill. Needless to say, I was livid at only having one useful value, but reasoned I didn't want to lose another 10% form gettin gmore HCl so I just dealt with it, using the only value I had.

Anyway, ended up with a concentration of 1.2 mol/L (but with more sig figs), which isn't /too/ bad seeing how the HCl was approx. 1 M in concentration.

I was quite upset though, stuffing up so royally.

At least I can do calculations well, I'm just a disaster when it comes to actually touching anything.


(If anyone is curious about any terms I used, go nuts with commenting and I'll explain. Because I like attention!)

EDIT: I have some pictures of things. Two are cut but one is included.


A pipette.


Your standard titration setup.


A titration in photo form for the easily confused