The Student Room Group

A-level Chemistry Study Group 2022-2023

Welcome to the A-level Chemistry Study Group! :woo:

This is where you can chat to others students taking your subject as you prepare for your A-level exams this summer

What can I do in these groups?

Almost anything! If you need help with a certain topic, want to rant about something you are struggling with or just want to support other students who are trying to prepare, this is the place for you. We want these to be a useful place for everyone no matter what you're looking for! :smile:

What can't I do in these groups?

Asking or offering copyright papers is against our site rules, and so is taking conversation off-site to do these things. Any posts doing this will be removed. That's the only rule :naughty:

Ice Breaker questions if you want to use them!

> What exam board are you on? (Vote in the poll as well!)

> What bits of the course are you feeling confident with?

> What areas are you struggling with a little?

> Have you found any resources online that have helped you prepare?

Specifications

Spoiler




Good luck with the next few months. Remember, ask for help, support where you can and together we can do this! :yes:

Scroll to see replies

Keeping this space for a list of resources or study tools that are recommended in this thread:
PMT - Chemistry Revision
Save My Exams - Past Papers
Chemrevise
SnapRevise
Seneca
Allery Chemistry - Youtube
MaChemGuy (OCR) - Youtube
Reply 2
Original post by Evil Homer
Keeping this space for a list of resources or study tools that are recommended in this thread:
PMT - Chemistry Revision
Save My Exams - Past Papers
Chemrevise
SnapRevise
Seneca
Allery Chemistry - Youtube
MaChemGuy (OCR) - Youtube


This might be helpful:smile: https://youtu.be/8lA7FdMwSiM
Original post by Fatima__
This might be helpful:smile: https://youtu.be/8lA7FdMwSiM


Thanks! I'm guessing this is your channel? Is this work free to access as I don't want to get you in trouble by promoting it and an exam board seeing it :smile:
Good luck to everyone sitting their Chemistry A-Level exams. :smile:
(edited 1 year ago)
> What exam board are you on? (Vote in the poll as well!)
OCR A
> What bits of the course are you feeling confident with?
Carbonyls and Transition Elements
> What areas are you struggling with a little?
Rates and A lot of mod 3.
> Have you found any resources online that have helped you prepare?

I don't use a lot of online resources for chemistry except past papers from StudyMind (tbf they got sloppy in preparing the later module topic past papers)
Reply 6
Original post by Evil Homer
Thanks! I'm guessing this is your channel? Is this work free to access as I don't want to get you in trouble by promoting it and an exam board seeing it :smile:

Hi, yes i just created bcz i have a-lot of resources that i bought last year during my A levels. so i thought that it will be good if everyone can get access them because some people cannot afford to buy.
:smile:
I did OCR biology and Chemistry and AQA maths
(edited 1 year ago)
> What exam board are you on?
OCR A

> What bits of the course are you feeling confident with?
I'm semi-confident on most of last years content - a part from amount of substance which always has been and probably always will be the bane of my existence

> What areas are you struggling with a little?
Amount of substance, rates (mainly the Arrhenius calculations) and carbonyls

> Have you found any resources online that have helped you prepare?
I use SME and PMT for practice qs and AlleryChemistry on yt for vids if confused
Reply 8
> What exam board are you on?
OCR A

> What bits of the course are you feeling confident with?
Inorganic chemistry I really like buffers

> What areas are you struggling with a little?

Organic chemistry is my weaker side and I'm struggling with practical techniques
Reply 9
What exam board are you on? (Vote in the poll as well!)
AQA
> What bits of the course are you feeling confident with?
year 12 and 13 physical topics (except Arrhenius :| ) and year 12 organic
> What areas are you struggling with a little?
Year 13 mechanisms, particularly the reagents, mass spec and periodicity. I hate it.
> Have you found any resources online that have helped you prepare?

Allery chemistry, pmt and Dr Clay
> What exam board are you on? (Vote in the poll as well!)
OCR A
> What bits of the course are you feeling confident with?
Equilibrium and rates, all the periodic table topics
> What areas are you struggling with a little?
Literally all of organic chemistry
> Have you found any resources online that have helped you prepare?

Chemguide
> What exam board are you on? (Vote in the poll as well!)
AQA

> What bits of the course are you feeling confident with?
Year 12 Organic

> What areas are you struggling with a little?
Year 13 Organic

> Have you found any resources online that have helped you prepare?
CGP guide, PMT and Organic chemistry tutor (youtube)

I am trying new study methods and resources so please let me know if you have any recommendations :smile:
Original post by Oinkeee
> What exam board are you on? (Vote in the poll as well!)
AQA

> What bits of the course are you feeling confident with?
Year 12 Organic

> What areas are you struggling with a little?
Year 13 Organic

> Have you found any resources online that have helped you prepare?
CGP guide, PMT and Organic chemistry tutor (youtube)

I am trying new study methods and resources so please let me know if you have any recommendations :smile:


Studymind has AQA A-Level chem notes and past paper questions and snaprevise also does AQA.
Hello current A level chemists!

I achieved an A* in (Edexcel) A level chemistry in the June 2022 exams.

As I’m currently on a gap year, it may well be helpful for me to keep my knowledge of A level chemistry alive by helping some of you guys, so feel free to ask questions and I’ll see what help I can offer.

A little while back, I posted my best advice here:

https://www.thestudentroom.co.uk/showthread.php?t=7253201&p=97549790&page=2#post97549790

(Thanks @Evil Homer for coming up with all these amazing thread ideas - keep up the good work)
Hi everyone,

Pls can I ask for some help.

I am currently working through AS AQA paper 1 4 mark maths questions, and just cannot seem to grasp them.

Does anyone have any advice, or know of any resources to help?
Original post by bellero12
Hi everyone,

Pls can I ask for some help.

I am currently working through AS AQA paper 1 4 mark maths questions, and just cannot seem to grasp them.

Does anyone have any advice, or know of any resources to help?

If it’s the moles and amount of substance questions, then try looking at a few model answers first. I’ll even write out a model solution below, including all of my reasoning to see if that is of any help:

Let’s make up the following exam-style question:

(6.9: A student decides to prepare sodium sulphate by reacting an excess of solid sodium hydrogencarbonate, NaHCO3, with sulphuric acid.

The balanced equation is given below:

2NaHCO3 + H2SO4 —> Na2SO4 + 2H2O + 2CO2

The student has 50 cm^3 of 0.30 mol dm^-3 sulphuric acid. Find the minimum mass of sodium hydrogencarbonate required to react completely with this volume of sulphuric acid.

So first and foremost, I’d begin by highlighting some important words and numbers in the question. The volume and concentration of the sulphuric acid should be underlined, as should the word ‘mass’, as that is what you are trying to calculate.

Next, I’d think about what I need in order to calculate what it is I need to find - I know that mass = relative formula mass x moles, so I’ll have to work out what the relative formula mass and the moles are.

As it’s the mass of sodium hydrogencarbonate I’m required to find, the relative formula mass can be found using the periodic table. The relative masses of sodium, hydrogen, carbon and oxygen can all be found and using the formula (NaHCO3), you can work out how many atoms of each element is present (1 Na, 1 H, 1 C and 3 O), so the Mr = 23 + 1 + 12 + 3(16) = 84 g mol^-1

To find the moles, it’s a bit trickier - but we can use the equation given earlier in the question to deduce how many moles of sodium hydrogencarbonate will react completely with all the acid. Moles of substance in solution = concentration (in mol dm^-3) x volume of solution (in dm^3). 50 cm^3 is 0.05 dm^3 (divide by 1000 to get from cm^3 to dm^3), so the moles of acid = 0.05 dm^3 x 0.30 mol dm^-3 = 0.015 mol. But if we look at the equation, for every 1 molecule of sulphuric acid that reacts, there are two sodium hydrogencarbonates that react, so the moles of sodium hydrogencarbonate = 2 x 0.015 mol = 0.03 mol

And to get our final answer, we can now use the equation mass = relative formula mass x moles.
84 g mol^-1 x 0.03 mol = 2.52 g

So the final answer in this case should be 2.52 g.

Ofc, not all 4 mark calculations will be exactly like this, but this example should teach you the following lessons:

-Look carefully at what it is the question is asking you to calculate and what information you are given. That way, it’s easier to work out which mole calculation(s) you need to use.

-Always underline key information and command words in the question.

-Make good use of your data booklet - sometimes the information (i.e relative masses) you need aren’t necessarily stated in the question.

I appreciate the example given wasn’t necessarily of the same difficulty as a 4-marker, so I’ll have a look at some AS past papers and get an idea of how to make some more helpful worked examples.
(edited 1 year ago)
Original post by anonymousgarly
pls cud u let me knw de answers to these questions!!
this is from de edexcel IAL chem October 2022 paper.

If these questions are from October 2022, I’m not sure you are meant to be sharing them, as teachers will be using the October 2022 papers as mocks. @Evil Homer can you clarify?
Is anyone else struggling to understand and do exam questions on Aromatics and Amines? Like I just don't understand what they are and their reactions/uses if anyone could help
Original post by SuperiorPotato
Is anyone else struggling to understand and do exam questions on Aromatics and Amines? Like I just don't understand what they are and their reactions/uses if anyone could help


Aromatics:

What they are:

Aromatics (as far as A level is concerned) are compounds that contain a benzene ring. This is basically any ring of 6 carbon atoms in which the 4th outer electron in each of these 6 carbon atoms delocalises (i.e it is shared with the 5 other carbon atoms via the overlap of the p-orbitals), adding extra stability to the ring.

Reactions:

Because of the high density of electrons, aromatics attract electrophiles. Because of the extra stability, they prefer not to undergo addition. Hence, they usually undergo electrophilic substitution reactions. With benzene, a catalyst and heating is required, because the stability of the ring is too great. With phenol and 1-aminobenzene, because the functional groups have lone pairs that add to the electron density of the ring, the electrophiles react much more easily with the ring, so a catalyst and heating are not required.

Amines:

What they are:

Amines are in my opinion, a little more difficult than aromatics. You have primary amines, in which an NH2 group is bonded to one carbon chain, secondary amines, in which an NH group is bonded to two carbon chains and tertiary amines, in which a nitrogen atom is bonded to three carbon chains.

Reactions:

Because the nitrogen atom has a lone pair, amines are capable of reacting with acids, so they are basic. In order of increasing basicity: primary < secondary < tertiary, as the carbon chains are electron donating, so the more of them that surround the nitrogen atom, the more available the lone pair is due to the increased electron density. Also because of the lone pair on the nitrogen atom, amines can act as nucleophiles, so primary and secondary amines can react with haloalkanes to form secondary and tertiary amines (nucleophilic substitution), respectively. Furthermore, primary and secondary amines can react with acyl chlorides to form N-substituted amides (nucleophilic addition-elimination).

(Note that amines should not be confused with amides, which are compounds where the nitrogen atom is bonded directly to a C=O group).

Uses:

As for the uses of amines, I assume you mean the following:

-If the amine is a diamine (i.e has 2 x -NH2 groups), then it can be used to synthesise condensation polymers.

-If the amine has been reacted in such a way that it forms a quarternary ammonium salt (i.e the nitrogen atom is surrounded by 4 alkyl groups and is now a cation), it is used to make disinfectants.

-Otherwise, assume that the amine is a precursor molecule that has uses in synthesis (you can say ‘it’s used to make pharmaceuticals’ or something).

As this isn’t a full analysis of either topic, feel free to ask about any aspects of these topics that I haven’t covered in this post.
Original post by TypicalNerd
Aromatics:

What they are:

Aromatics (as far as A level is concerned) are compounds that contain a benzene ring. This is basically any ring of 6 carbon atoms in which the 4th outer electron in each of these 6 carbon atoms delocalises (i.e it is shared with the 5 other carbon atoms via the overlap of the p-orbitals), adding extra stability to the ring.

Reactions:

Because of the high density of electrons, aromatics attract electrophiles. Because of the extra stability, they prefer not to undergo addition. Hence, they usually undergo electrophilic substitution reactions. With benzene, a catalyst and heating is required, because the stability of the ring is too great. With phenol and 1-aminobenzene, because the functional groups have lone pairs that add to the electron density of the ring, the electrophiles react much more easily with the ring, so a catalyst and heating are not required.

Amines:

What they are:

Amines are in my opinion, a little more difficult than aromatics. You have primary amines, in which an NH2 group is bonded to one carbon chain, secondary amines, in which an NH group is bonded to two carbon chains and tertiary amines, in which a nitrogen atom is bonded to three carbon chains.

Reactions:

Because the nitrogen atom has a lone pair, amines are capable of reacting with acids, so they are basic. In order of increasing basicity: primary < secondary < tertiary, as the carbon chains are electron donating, so the more of them that surround the nitrogen atom, the more available the lone pair is due to the increased electron density. Also because of the lone pair on the nitrogen atom, amines can act as nucleophiles, so primary and secondary amines can react with haloalkanes to form secondary and tertiary amines (nucleophilic substitution), respectively. Furthermore, primary and secondary amines can react with acyl chlorides to form N-substituted amides (nucleophilic addition-elimination).

(Note that amines should not be confused with amides, which are compounds where the nitrogen atom is bonded directly to a C=O group).

Uses:

As for the uses of amines, I assume you mean the following:

-If the amine is a diamine (i.e has 2 x -NH2 groups), then it can be used to synthesise condensation polymers.

-If the amine has been reacted in such a way that it forms a quarternary ammonium salt (i.e the nitrogen atom is surrounded by 4 alkyl groups and is now a cation), it is used to make disinfectants.

-Otherwise, assume that the amine is a precursor molecule that has uses in synthesis (you can say ‘it’s used to make pharmaceuticals’ or something).

As this isn’t a full analysis of either topic, feel free to ask about any aspects of these topics that I haven’t covered in this post.

OMG thank you so much you absolute legend

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