Thinking ahead
So you're in a rush. There's a reaction coming off in half an hour which you want purified by the end of the day, washing up is piling up on every available surface. Your boss has just informed you (surprise!) that he wants to send off samples by the end of the week. You're following a scheme given in an article and all it says is to charge the flask with the reagents.
To cut a long story short I got the mixture up to about 70 degrees (Celsius) and had methanol (byproduct) boiling off before I realised that just chucking the catalyst in probably wasn't a fantastic idea. There is nothing like the feeling of standing next to a flask that is refluxing on its own. Anything that could reasonably have been done about it were
precautions which should already have been in place. There were abortive attempts to obtain an ice/water bath (we have neither tubs nor ice) or any kind of circulating cooling system (um, I don't even know what I was thinking - I've seen my lab, running water was a stretch) but as it was I just stood there and desperately hoped that, a) the temperature stopped rising before the water boiled off and b) my boss didn't walk in. These things have got to stop happening to me.
Anyway, my lesson for today: Stop adding reagents before you lose control of the reaction. (And don't trust anything you read in a scientific journal - lies, damned lies)
To cut a long story short I got the mixture up to about 70 degrees (Celsius) and had methanol (byproduct) boiling off before I realised that just chucking the catalyst in probably wasn't a fantastic idea. There is nothing like the feeling of standing next to a flask that is refluxing on its own. Anything that could reasonably have been done about it were
precautions which should already have been in place. There were abortive attempts to obtain an ice/water bath (we have neither tubs nor ice) or any kind of circulating cooling system (um, I don't even know what I was thinking - I've seen my lab, running water was a stretch) but as it was I just stood there and desperately hoped that, a) the temperature stopped rising before the water boiled off and b) my boss didn't walk in. These things have got to stop happening to me.
Anyway, my lesson for today: Stop adding reagents before you lose control of the reaction. (And don't trust anything you read in a scientific journal - lies, damned lies)