AS Chemistry- helping each other out!
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Original post by Super199
http://filestore.aqa.org.uk/subjects/AQA-CHEM2-W-QP-JUN10.PDF
How do you work out the minor product q.
6aiii.
How do you work out the minor product q.
6aiii.
The H can be added to either carbon of the double bond.
I don't think it would be a problem as long as you have the correct radicals and compounds. Not sure, though. 
Should be fine both but it is always safe to go with structural formula unless stated otherwise
I think I might have looked at the wrong paper, can't seem to find the question.
Could you link it?
Energetics is not my strong suit, but I can try.
Could you link it?
Energetics is not my strong suit, but I can try.
Original post by thymolphthalein
I think I might have looked at the wrong paper, can't seem to find the question.
Could you link it?
Energetics is not my strong suit, but I can try.
Could you link it?
Energetics is not my strong suit, but I can try.
http://filestore.aqa.org.uk/subjects/AQA-CHEM2-W-QP-JUN10.PDF
I'm a tad confused with this as well.
Surely this is an exothermic reaction the reactants > products?
http://filestore.aqa.org.uk/subjects/AQA-CHEM2-W-QP-JAN11.PDF
7bii. How does electrophillic addition reaction with dienes?
7bii. How does electrophillic addition reaction with dienes?
hey.
if they ask for an equation and you write it as a displayed formula but mark scheme has it as molecular formula do you still get the marks?
this is for ocr f322
if they ask for an equation and you write it as a displayed formula but mark scheme has it as molecular formula do you still get the marks?
this is for ocr f322
Original post by Super199
http://filestore.aqa.org.uk/subjects/AQA-CHEM2-W-QP-JUN10.PDF
I'm a tad confused with this as well.
Surely this is an exothermic reaction the reactants > products?
I'm a tad confused with this as well.
Surely this is an exothermic reaction the reactants > products?
More on bond enthalpy calculations here: http://www.chemguide.co.uk/physical/energetics/bondenthalpies.html
I could be very very wrong though, but I think it makes sense...
What is the functional group isomer of an aldehyde? specifically butanoic acid
What is the positional group isomer of butan-1-ol.
What is the positional group isomer of butan-1-ol.
Original post by Super199
What is the functional group isomer of an aldehyde? specifically butanoic acid
What is the positional group isomer of butan-1-ol.
What is the positional group isomer of butan-1-ol.
Position group isomer of butan-1-ol would be butan-2-ol. (You move the position of the functional group)
The functional group isomer of an aldehyde is a ketone. (Both have the same molecular formula and both have carbonyl groups but they are attached in two different positions. CH3COCH3 (ketones have the C=O on an interior carbon) but CH3CH2CHO (aldehydes have it on an end carbon).
The functional group isomer of a carboxylic acid would be an ester, if I recall correctly.
(edited 8 years ago)
Original post by thymolphthalein
Position group isomer of butan-1-ol would be butan-2-ol. (You move the position of the functional group)
The functional group isomer of an aldehyde is a ketone. (Both have the same molecular formula and both have carbonyl groups but they are attached in two different positions. CH3COCH3 (ketones have the C=O on an interior carbon) but CH3CH2CHO (aldehydes have it on an end carbon).
The functional group isomer of a carboxylic acid would be an ester, if I recall correctly.
The functional group isomer of an aldehyde is a ketone. (Both have the same molecular formula and both have carbonyl groups but they are attached in two different positions. CH3COCH3 (ketones have the C=O on an interior carbon) but CH3CH2CHO (aldehydes have it on an end carbon).
The functional group isomer of a carboxylic acid would be an ester, if I recall correctly.
So the functional group isomer of butanoic acid would be butanone?
Surely butanone has one fewer oxygen?
Oh wait you said ester. How the hell do you draw an ester
(edited 8 years ago)
Original post by Super199
So the functional group isomer of butanoic acid would be butanone?
No.
Butanone: C4H8O
Butanoic acid: C4H8O2
The molecular formula is different.
Propanal: C3H6O
Propanone:C3H6O
Propanoic acid: C3H6O2
Methyl Ethanoate: C3H6O2
http://www.chemguide.co.uk/basicorg/isomerism/structural.html
Who does AS chemistry AQA because I want to revise with someone but I can't find any threads for people who do AQA chem
Original post by hideNfreak
Who does AS chemistry AQA because I want to revise with someone but I can't find any threads for people who do AQA chem
http://www.thestudentroom.co.uk/showthread.php?t=3353273&page=28
I'm doing AQA, there is a thread here
Original post by hibaj
hey.
if they ask for an equation and you write it as a displayed formula but mark scheme has it as molecular formula do you still get the marks?
this is for ocr f322
if they ask for an equation and you write it as a displayed formula but mark scheme has it as molecular formula do you still get the marks?
this is for ocr f322
Unless they specify which form they want it in, then you should get the marks. In mark schemes, there's usually a sentence saying on the question saying which formulae are accepted, and it's usually skeletal, displayed and structural (more may be accepted but idk).
Original post by lukejoshjames
Unless they specify which form they want it in, then you should get the marks. In mark schemes, there's usually a sentence saying on the question saying which formulae are accepted, and it's usually skeletal, displayed and structural (more may be accepted but idk).
Ya, thanks. Was wondering what happens if they don't say that in the mark scheme and there's on one formula shown
Hi, do the intermolecular forces of halogenoalkanes decrease or increase down the group?
Because I swear the boiling points of halogenoalkanes increases down the group due to larger & more halogen atoms. So shouldn't their intermolecular forces increase too?
But a flashcard said that the C-X bonds get weaker as you go down due to shared electrons in a bond getting further from the halogen nucleus
Because I swear the boiling points of halogenoalkanes increases down the group due to larger & more halogen atoms. So shouldn't their intermolecular forces increase too?
But a flashcard said that the C-X bonds get weaker as you go down due to shared electrons in a bond getting further from the halogen nucleus
(edited 8 years ago)
Bond forming is exothermic
Bond breaking is endothermic
Bond enthalpy is the enthalpy change when breaking a mole of gaseous bonds to form gaseous atoms. So it is endothermic.
However this reaction is exothermic because bonds are forming and bond enthalpy's sign is changed from + to - with same magnitude.
So the bond enthalpy of products are bigger but when calculating the enthalpy change of the reaction using bond enthalpy you'd change the sign on the bond enthalpy of products to - so when added together with bond enthalpy of reactants the result ends up being negative = exothermic
Bond breaking is endothermic
Bond enthalpy is the enthalpy change when breaking a mole of gaseous bonds to form gaseous atoms. So it is endothermic.
However this reaction is exothermic because bonds are forming and bond enthalpy's sign is changed from + to - with same magnitude.
So the bond enthalpy of products are bigger but when calculating the enthalpy change of the reaction using bond enthalpy you'd change the sign on the bond enthalpy of products to - so when added together with bond enthalpy of reactants the result ends up being negative = exothermic
Original post by KINGYusuf
Hi, do the intermolecular forces of halogenoalkanes decrease or increase down the group?
Because I swear the boiling points of halogenoalkanes increases down the group due to larger & more halogen atoms. So shouldn't their intermolecular forces increase too?
But a flashcard said that the C-X bonds get weaker as you go down due to shared electrons in a bond getting further from the halogen nucleus
Because I swear the boiling points of halogenoalkanes increases down the group due to larger & more halogen atoms. So shouldn't their intermolecular forces increase too?
But a flashcard said that the C-X bonds get weaker as you go down due to shared electrons in a bond getting further from the halogen nucleus
Intermolecular forces of halogenoalkanes increase down the group because there are more electrons so stronger dispersion force.
About C-X bonds getting weaker, it has got nothing to do with the boiling point. You probably had it written down for the rate of hydrolysis of halogenoalkanes.
Can someone describe/ show me the different boltzmann distribution graph for temperature, pressure and catalyst? Thanks
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