Organic Chem questions

bonkysleuth SG

1 Give one advantage of disposing waste polystyrene by burning.

Not sure of this but I'll make a guess. Is it that it is non-biodegradable and if we dispose it by other method(eg. burying it) it will take up land space causing land pollution.

I think my answer is quite vague. Can I have some better suggestions?

Next,

2 Beer cans are usually made of aluminium. Normal plastic bottles are permeable to some oxygen gas and this will cause beer to turn stale. A new plastic, poly(ethylvinylidene alcohol), is 300 times less permeable than normal plastics, and is seen as a good replacement for aluminium cans.

Other than cost, suggest 1 advantage of using poly(ethylvinylidene alcohol) instead of aluminium.

Thanks.

ThunderFbolt SG

Taken from Wiki:

If polystyrene is properly incinerated at high temperatures, the only chemicals generated are water, carbon dioxide, some volatile compounds, and carbon soot. If properly burned, one ton of foam cups produces 0.2 ounces of ash.

For 2, maybe the polymer is easier to recycle than aluminium?

anpanman SG

Taken from Wiki:

For 2, maybe the polymer is easier to recycle than aluminium?

thanks for posting up these 2 useful questions bonky! and thanks ThunderFbolt for answering TS's questions. By the way, is poly(ethylvinylidene alcohol) really easier to recycle than alcohol?

And some Organic Chem questions for you all too.

If fat molecule reacts with NaOH, products formed are an alcohol and soap(sodium salt of long carbon chains of carboxylic acid). I understand the alcohol is ethanol but what about the latter? Do give a response if possible. (:

dkcx SG

And some Organic Chem questions for you all too.

You sure its ethanol? I thought all fats will give glycerol instead due to them mostly be triglycerides.

The salt is simply the entire long chain molecule with the OH of the COOH replaced with Na if i didn't remember wrongly

UltimaOnline SG

You sure its ethanol? I thought all fats will give glycerol instead due to them mostly be triglycerides.

The salt is simply the entire long chain molecule with the OH of the COOH replaced with Na if i didn't remember wrongly

Yes, that's right. With NaOH, what occurs is base-promoted hydrolysis of the ester functional groups in triglyceride fats, to generate alkyltriol (ie. the alcohol component of an ester) and sodium alkylcarboxylate salt (ie. the deprotonated conjugate base of the carboxylic acid component of an ester).