OCR Chemistry F322~ 4th June 2013~ AS Chemistry

So how does everyone feel about this paper, im new to this thread, i think it could either go quite well or really bad...

Few questions for anyone to try....
'Describe the green house affect, and how it is created (8 marks)

3 greenhouse gases : carbon dioxide, water vapour, methane
Their covalent bonds absorb infra red radiation and vibrate.
Strength of greenhouse gases dependant on atmospheric concentration and ability to absorb infra red
The greenhouse gases emit this infra red radiation onto earth surface causing it to heat up

That's all I can think of but I doubt such a question would come

Is there any chance someone could please explain question 2d on the May 2012 paper? It says

Ethane-1,2-diol reacts with an excess of ethanoic acid CH3COOH, in the presence of an acid catalyst. A compound is formed with the molecular formula C6H10O4. Draw the structure of this compound.

Thanks

righto
first things first draw out ethane-1,2-diols
H H
I I
H-C-C-H
I I (you can put the diols whereever you like- but remember keep it simple)
OH OH

Next step, in the question we are told it reacts with 'excess ethanoic acid'
'ethanoic acid' should remind you of esterification
we also know that the molecules will react with excess ethanoic acid to form an ester
O H
II I
ethanoic acid= C-C-H
I I
OH H

ester= -O- bonds
excess= as many -O- bonds as possible!!!
so you should end up with:
H O H H O H
I II I I II I
H-C-C-O-C-C-O-C-C-H
I I I I
H H H H

in red is your original ethane-1,2-diol
in black are the 2 ethanoic acid molecules- there are 2 because each OH reacted with the OH of the ethane-1,2-diol

Can soneone help me with this? I have no idea how to do this question... like No idea!!!!!

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Can soneone help me with this? I have no idea how to do this question... like No idea!!!!!

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I (tried to) explain this to someone yesterday.
I attached a drawing of my cycle on page 27, its the last post on that page
basically the cycle doesnt look like a normal hess's law one, but the principles are the same.

Anyone up for revision questions
Why can tertiary alcohols be oxidised
Assume you mean CANT be oxidised because the carbon with OH on it has 3 other R groups on it



Problems of high concentrations of CO and NO
not really sure what the questions means...
Define elctrophile
electron pair acceptor
Conditions for fermentation yeast and 37 degrees
Describe conditions for productions of Magerinedon't remember this.. is it on the spec

Oh I think I get it. So you added Carbon for both sides right? But for N2 + 0.5O2 bit, I understand Carbon + oxygen = CO hence you right at the bottom.. but then N2 + C doesn't make sense?! (Is that why you ignored it?)

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Answers in bold

not exactly. basically, what you do is look at ur overall equation, then draw arrows down with the corresponding equations given in that table. so, for the reactants, the corresponding equation would be the c+0.5o2=co ( just look at which one has the same reactants/at least one reactant is the same) so for the product n2o, the arrow coming down must be for the equation c+n20=co + n2. does that make more sense? it doesnt really matter what products you get after you've drawn the arrow, the main thing is that you've got the numbers in the right places

Could you be kind enough to draw it out, as I was was struggling at that kind of question as well


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For co it was toxic and no can cause acid rain

For magerine it's the hydrogenation reaction using hydrogen in 150c and nickel catalyst

Fr year include anaerobic conditions

Anyone up for revision questions
Why can tertiary alcohols be oxidised
Problems of high concentrations of CO and NO
Define elctrophile
Conditions for fermentation
Describe conditions for productions of Magerine

ok

Define hydrolysis?
Compare rate of reaction of halogenalkane hydrolysis?
whats the difference between structural isomers and sterioisomers?
Whats the generic formula for a cycloalkene ?
Whats the prefix for a 9 carbon side chain?
How are alkenes formed?

i've done it already, page 27 last post ive attached it

not exactly. basically, what you do is look at ur overall equation, then draw arrows down with the corresponding equations given in that table. so, for the reactants, the corresponding equation would be the c+0.5o2=co ( just look at which one has the same reactants/at least one reactant is the same) so for the product n2o, the arrow coming down must be for the equation c+n20=co + n2. does that make more sense? it doesnt really matter what products you get after you've drawn the arrow, the main thing is that you've got the numbers in the right places

Still don't get it, hate that question I cannot do Hess law cycles, my teacher only said you need to only know for combustion it's reactants - products and for formation you do Products - Reactants. Can out help me out please????


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