OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012

Hey,

You do have the correct idea, maybe its going wrong with what your working out? Your not including water or anything right?
Basically, first work out the moles of butan-1-ol and butyl ethanoate. Now if you look at the equation, ideally your supposed to get the same amount in moles right cos its in 1:1 ratio? But its not going to be so with the moles your going to get you apply the formula, with actual yield being that of what you actually got (moles of butyl ethanoate) divided by theoretical (moles of butan-1-ol) That help? Try again now and you should get it!

Any other A2 resitters around?

Any other A2 resitters around?

Hey, I'm resitting this paper

Yh I'm resiting this too

Any other A2 resitters around?

This is my second resit of this paper Got 102 last summer, 118 in June... Still think I can improve that so 3rd time lucky!

wow! u genius I would be happy with 118...good luck anyway what UMS mark do you ant to get?? and have you got any tips thanks

any ideas of what may come up for the long markers..i think it may be those infrared spectrums where we have to find out structure of a compound i hate them.

They're not too bad! You should have some sort of idea from the context of the question (it usually gives you an empirical formula, or tells you that it's the product of an oxidation of an alcohol, for example), so you'll have an idea of what sort of functional groups are there (if it's from oxidation of an alcohol it'll either be a carby acid, a ketone or an aldehyde). Test each of those hypotheses mentally by looking for those functional groups on the IR spec. When you have one that fits, and only then, start to write your answer

Anyone know what raw mark got full ums in June 2011?

a bit confused if anyone's done the jan 2012 paper..Q) 2b).. i understand the C=O bit and that it can't be a carboxylic acid, but how do you get the Mr to be 86 and the structure? please help!

Any other A2 resitters around?

If a 9mark question on the HARBER Proces comprimising condition comes up here's what to right:

If the pressure is increased, the rate of reaction is inceased as there are more particles closer together so more frequent collisons. The position of equilibrium moves to the right hans side as there are fewwer number of mole on this side so more ammonia is produced. However, if the pressure is too high this may be dangerous and expensive.

If the temperature is increared the rate of reaction increases as particles have more enrgy so exceed activation enrgy. The position of equilibrium moves to the left hand side as the forward reactionis exothermic. Hwever, if the temperature is too high ther wil be less yield of amonia. If the temperature is too low ther will be a slowr rate of reaction...