September 9, 2008

Gruelling Chemistry Practicals

Before the start...

Group member 1: " They say its pretty tough. We should've prepared for this and come."

Group member 2: " Kukka cool mama antha scene ledu. "

Me: " He said the same thing last time. Lite. "

But it wasn't 'lite'. And we understood that sir was'nt going to spare us today when he said that we've got to do the experiment individually. We started reading the procedure as we had not read anything.
Sir( mockingly ) : " Not read, eh? Thought you'll read here. Very good, one mark cut." Well, presuming that the world was still rosy outside we started off.

Basically, the experiment was about getting acetanalide from the reaction of aniline and acetic anhydride. Then weigh the amount, take four grams out of it, recrystallize in order to obtain a pure sample.

First, we had trouble with measuring out the exact amounts of aniline ( smelly ). Then we managed to get some rashes on the wrist thanks to some of the glacial acetic acid that we dropped on ourselves while measuring it out.
When the reaction started sharp vapors issued from the flask, giving the feeling of knives being groped in the nose. It was so strong that tears came out naturally from our eyes, sir came and merely glanced at the sample and said that we left out some moisture in the flask and asked us to do it again. Some more aroma, some more tears. Then we got down to refluxing it. Some time to relax we thought. 30 minutes was the prescribed time. But, sir had other plans...

The night before we sat down uptil 3.00 in order to finish the record, the readings and the graphs. ( We knew we shouldn't have left it for the last minute. At the same time we knew that we'll be postponing it to the last minute anyways ). We did the graphs correctly enough.
He wasn't satisfied though, said it should have curved a little more, the scale was too short and the writing not neat enough. All three of us were immediately seized by a mad desire to take his head and dip it in the reaction flask.

Group member 1: "Does he expect us to write like school kids? ( Whispers ) Sir aap kounsey iskool se ho ?"

Done with the correction, he asked us to come the next day with the readings again as he was not able to look at our dirty work on such a pleasant day. If there was a test tube in my hands it would surely have cracked. " I'll take your viva at the same time... "

Back to the experiment.
We got the shit.. oops, the acetanalide, we filtered it, put it in the oven, weighed it, took 4gms; went to purify it by heating it in a conical flask on a flame and again filtered it, put it in the oven, finally weighed it. We got some 1.973 gms ( Sir : " You should get it below 2 gms" ). Two hours were up. Happily, with ash-burnt faces, we announced the result.

Sir: " Do it again. It should come close to 1.6"

Group Member 2: " Nee yebba. Savv bey nen cheyyatledd."

Somehow, we managed it again and got 1.710.

Sir : " Mmmmm. Not good enough."
Lab assistant :" Doosra class aa raha hain sir. Inko bhejna hi padega. "

Sir:" Offo. You boys are always late, next time along with the other experiment complete this..."
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