Seeing how much I failed at chemistry olympiad, it really makes me wonder how I managed to do so well in class. Perhaps it's due to the fact that the 'normal' chemistry that we are learning consists of more topics that can interest me, for example QA, redox. On the other hand, chemistry olympiad consists of the visual topics of organic chemistry, which involves chirality and all other stuff which I dislike. And seeing how fail I was at physical chemistry as well, sometimes I really wonder whether I can actually do chemistry the same way as I did it in class now, or worse.
Because apparently JC chemistry consist of more topics on physical chemistry, so apart from ideal gas law we have thermochemistry and the rest. And organic chemistry takes up 40% of all the topics taught. That is something to consider about.
On the other hand, I am absolutely NOTHING without chemistry. If I gave up on chemistry, I would probably just turn to any normal HCI students, except that I do not have any other talent, is not sociable, is not a good leader, does not possess any characteristics that people may like, and is average with studies and very dead with physics and maths (and english). That would be me without chemistry. That is how much chemistry mean to me. I suppose I'm too prideful to admit that I am nothing without chemistry, because that's the only subject that I can 'own' in. But now seeing my epic failure in chemistry olympiad, I may start to lose the confidence.
.
On another note, today's bio SPA was spastic. In the sense that the method you are supposed to use is around the same: titration. However, the procedures vary, resulting in all sorts of variations of procedures such that Mrs Goh decided that she would look through thamsy, weibo, johnny, dominic and my paper first in order to set the standard (because apparently we all did titration but using different methods.)
My method would be the extremely long and chim and what people call 'waste of time' method, but seeing that you do not need to carry out the actual experiment and that it only needs to be logical, my method may actually be accepted. So basically the aim is to determine concentration of lipase on hydrolysis of fats, which produces fatty acids and glycerol. The fatty acids will cause a decrease in pH hence causing the indicator, bromothymol blue to turn yellow. And sodium hydroxide is provided to neutralise the fatty acids formed. And so here is a brief outline of my method:
Add bromothymol blue to milk and add equal volume of lipase of diff concentration to equal volumes of milk. Time immediately. When the mixture turns yellow, add sodium hydroxide dropwise until it turns green (colour at pH 7). Then when it turns yellow again, add more sodium hydroxide to turn it back to green. Continue this process until the mixture remains green. Then record the time taken for the mixture to achieve this.
So basically, I assume that the reaction will surely end at one time, and thus all the fats would be hydrolysed to fatty acids and glycerol, only the time taken would be different. When the lipase concentration is low, hydrolysis occur at a lower rate, and thus fatty acids would be produced slowly. Hence a longer time is required for sodium hydroxide to completely neutralise all the fatty acids as they are produced at a slower rate, hence a longer waiting time.
On the other hand, a high concentration of lipase will cause fatty acids to form at a faster rate, hence the rate in which sodium hydroxide is added will increase, resulting neutralisation of all fatty acids formed from hydrolysis to be complete within a shorter time. Hence it can show how the lipase concentration affects by measuring the time taken for the mixture to remain green.
The main problem here is that we do not know how long it will take. However, since the experiment was not carried out, we do not know how short it will take as well. So if you are looking at the logic of the experiment, it does sound logical, only rather unrealistic because it may take a long time, and you have to repeat the same procedures using 5 more concentration of lipase. But oh well, the SPA is over, let's not worry too much about it. There's still physics and chem SPA tmr.
Wow I wrote so much today, what an improvement.
No comments:
Post a Comment