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OCR Chemistry F322~ 4th June 2013~ AS Chemistry

Reply 2140

Geronimo!

7

Original post by TheFootyKing19

Yeah on each paper 2/3 come up!

Hope all 3 turn up tho :wink:

and definitions is a big chunk to this exams

As is Boltzmann, equilibrium questions, green chem, maths calc

I think q = mcdeltaT will come up for 10 marks :biggrin:

as hasn't been past 2 papers.

Definition of Enthalpy change of COMBUSTION and state standard conditions (3)
Work out Kj (2)
Work out moles (1)
Work out energy change, 3 sig figs (3)
Why combustion values different (1/2)

:biggrin:

How would you work out the energy questions?! :confused:

Reply 2141

JimmyA*

5

Original post by Zzzyax

perhaps someone can help me whats the difference between a alkane and a hydrocarbon, i have lots of revise to do tonight. and what does nucleophile actually mean?

An alkane is a hydrocarbon. An alkane is a homologous series which has a general formula of CnH2n+2. A hydrocarbon is a molecule which contains carbon and hydrogen only.

Reply 2142

simifeltham

Original post by Geronimo!

How would you work out the energy questions?! :confused:

deltaH=q/n

Reply 2143

Hello...

Original post by Zzzyax

perhaps someone can help me whats the difference between a alkane and a hydrocarbon, i have lots of revise to do tonight. and what does nucleophile actually mean?

A hydrocarbon is a molecule that contains hydrogen and carbon ONLY
Alkanes are hydrocarbons as they have the general formula C_NH_2N+2A nucleophile is an atom (or group of atoms) that is attracted to an electron deficient centre or atom. It is an electron pair donor

Reply 2144

ReginaPhalange29

Does anyone have a list of reactions with conditions/catalysts that we need to know?

Posted from TSR Mobile

Reply 2145

Lagukage4

Original post by Zzzyax

perhaps someone can help me whats the difference between a alkane and a hydrocarbon, i have lots of revise to do tonight. and what does nucleophile actually mean?

Hydrocarbon - Contains Carbon and Hydrogen only
Alkane - it is a hydrocarbon with a general formula CnH2n+2
Nucleophile - An electron pair donor :smile:

Reply 2146

Blashnet

8

hope there isn't loads of green chemistry! :mad:

Reply 2147

buzzing22

Is it likely to be on the p block? Because we did that for our isa..

Reply 2148

Hello...

Original post by simifeltham

It is indeed, it got me confused why it was 3 at first but it makes sense. It would be harsh if they asked a question like that. only expect 2[O] or [O]

Never know, it could be one of those q's that they throw in to make people trip up...

CH3(CH2)₂COOH + CH3CH2OH------->
[Conc. Sulphuric Acid + Heat]

Reply 2149

greenmind

Help urgently needed on how to answer question 6 from the Jan'12 paper

Link to the markscheme is http://www.ocr.org.uk/Images/59185-mark-scheme-unit-f322-chains-energy-and-resources-january.pdf

Reply 2150

Sam_1996

Original post by ReginaPhalange29

Does anyone have a list of reactions with conditions/catalysts that we need to know?

Posted from TSR Mobile

Main ones
Alcohol to Alkene heat concentrated H2SO4
Alkene to alcohol 300 degrees,60 ATM,concentrated H3PO4 and h20(g)
Alkene to alkane 150 degrees,nickels catalyst and h2

Also need to know alcohol oxidation
Reflux,K2Cr2O7/H2SO4

Reply 2151

Ché.

Original post by Lagukage4

just curious... if its CH3COCH2COOH isnt the 'CO' in that a carboxyl group rather than C-O-C..? making it a ketone and carboxylic acid combined? :smile:

It comes like that, doesn't it!?
Strange Chemistry.
From our inferences, it sounds about right...
Haha!

Posted from TSR Mobile

Reply 2152

mari_lynne

hey guys could anyone help explaining to me bond enthalpy questions? when you have to work out the bond enthalpy of a molecule knowing normally the products and △H, would be so appreciated! :smile:

Reply 2153

Kits

10

Original post by niceguy95

240 ums for A

Med b assuming that's 46 raw marks so 68 ums

39/40 is 59 ums

So you need about 113/150

How many raw marks is that?

Reply 2154

niceguy95

14

Which type of Questions do we draw the O-H bond when showing structure

Reply 2155

buzzing22

Original post by TheFootyKing19

Yeah on each paper 2/3 come up!

Hope all 3 turn up tho :wink:

and definitions is a big chunk to this exams

As is Boltzmann, equilibrium questions, green chem, maths calc

I think q = mcdeltaT will come up for 10 marks :biggrin:

as hasn't been past 2 papers.

Definition of Enthalpy change of COMBUSTION and state standard conditions (3)
Work out Kj (2)
Work out moles (1)
Work out energy change, 3 sig figs (3)
Why combustion values different (1/2)

:biggrin:

Which are the 3 mechanism!?

Reply 2156

simifeltham

Original post by hello...

never know, it could be one of those q's that they throw in to make people trip up...

Ch3(ch2)₂cooh + ch3ch2oh------->ch3ch2ch2cooch2ch3 + h20
[conc. Sulphuric acid + heat]

ch3ch2ch2oh ---->
h2so4 reflux

Reply 2157