A little quiz

I'll be away until 11 dec, hopefully coming back with good news, but here's a little quiz. Click here Will post answers and explanations when i get back

Be warned... it's not easy :-) Draws on sciences, current affairs / politics / economics, philo, geog, and some humour. Where there is no logical answer, answer as I would. Haha all the best, i don't expect anyone to pass!

Scoreboard

Acronym-ase

Ok taking a break from IJSO prep... decipher these bio acronyms!

ACTH ADH ANF CAM CNS cGMP cDNA ECM GABA Hfr IgM MHC p53 PDE PEP Pfr PNS PTH RAAS REM RuBP

Quotable quotes #2

One day... on the H2 Chem debrief thread on sgforums... (notice especially the last line)


A: Quite hard man..... Cambridge really transform into something new liao

B: r u talking bout the 3 carbonyl compounds? any idea what are those 3?
i got propanone, propanal, methanal but then i cant distinguish between methanal and propanal Crying or Very sad so i guess theyre wrong? also whats the type of reaction when amide becomes N- Na+??

C: the 3 correct ones should be methanal, ethanal and propanone. to distinguish propanone, just use Tollens' as it won't give silver mirror. then between methanal and ethanal, add aqueous alkali iodine. ethanal will give yellow ppt while methanal won't. When amide becomes N- Na+, it is an acid-base/neutralisation reaction (your sodium salt).

B: My friend say....its not ethanal.....its ethanoic acid...... and ethanoic acid has a carbonyl group as well....he gave a lot of explanation and I still don't understand at all....=/

C: Calcium methanoate gives methanal on heating, whereas the calcium salts of other carboxylic acids give ketones. If calcium methanoate is heated with the calcium salt of another carboxylic acid, the products will be mixed eg calcium methanoate plus calcium ethanoate will give methanal, propanone, and also ethanal.

B: how are we supposed to know this? its nowhere in the syllabus i can think of...
cambridge is really trying to kill us...

C: I guess they want us to learn the art of deduction. My comment: isn't it quite obvious that the products will be mixed? If A produces B, and X produces Y, then A and X will produce B and Y assuming A&X and B&Y don't interact

A: C which jc u from??u seem so lihai..ahhh think the time restrain of the paper make it tough :-(

C: which other jc will the chem dept force-feed and drill chem stuffs into your until you resemble nothing more than battery farm animals stuffed with chemical additives ready to be sent to the slaughterhouse known as A levels chemistry? of course it's rjc.

Brainless humour

Btw SBS is getting some new Scania buses to replace outgoing Merc O405 buses. I want them on no. 5 and no. 24 XD