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Reply 120
Original post by Gulzar
Sure thing (have u not revised the first bit? ) :smile:

What is a zwitter ion and explain the isolectric point of an amino acid?


I am using a weird technique, I find that reading from the first page to the end is boring and makes me want to sleep, so to make revision weird and interesting , I read staff from the end to the first page, it actually works better for me :tongue:


Zwitterion is a dipolar ionic form of an amino acid by the donation of a hydrogen ion from the carboxyl group to the amino group and both charges are present which results in the overall charge cancelling each other out. Isoelectric point is a point in a PH in which the amino acid exists as a zwitterion.
Reply 121
Original post by kevloui
Yea thats great! I havent covered the whole module yet, so I dont know about MMR and stuff, but anything before.


ok , how did you do in F325, I am going to do it again, I was only 3% off an A!


Describe two methods on how to make ester and give three main uses of ester (6)
Reply 122
Original post by otrivine
I am using a weird technique, I find that reading from the first page to the end is boring and makes me want to sleep, so to make revision weird and interesting , I read staff from the end to the first page, it actually works better for me :tongue:


Zwitterion is a dipolar ionic form of an amino acid by the donation of a hydrogen ion from the carboxyl group to the amino group and both charges are present which results in the overall charge cancelling each other out. Isoelectric point is a point in a PH in which the amino acid exists as a zwitterion.


Seems to be working :biggrin: CORRECT

My go :wink:
Reply 123
Original post by Gulzar
Seems to be working :biggrin: CORRECT

My go :wink:


hahaha , thanks

Give one use of benzyl ethanoate and state the functional group (2)
Reply 124
Original post by otrivine
hahaha , thanks

Give one use of benzyl ethanoate and state the functional group (2)


Im afraid I dont know a use (polymer building maybe)

The funstional group is an ester attached on the benzene ring.
Reply 125
Original post by Gulzar
Im afraid I dont know a use (polymer building maybe)

The funstional group is an ester attached on the benzene ring.


good!

An example of the use could be ,perfumes.

My turn .
Reply 126
Original post by otrivine
good!

An example of the use could be ,perfumes.

My turn .


Give the reaction that forms Kevlar. Include the reactants and the name of this type of polymerisation.
Reply 127
Original post by Gulzar
Give the reaction that forms Kevlar. Include the reactants and the name of this type of polymerisation.


Kevlar = is a polyamide and undergoes Condensation polymerisation.

The reactants involved are:-

Benzene-1,4-diamine + Benzene-1,4-dicarboxylic acid

As a result of condensation(removal of water) the two compounds join together to form a long repeat unit and forms kevlar used in bulletproof vests for example.
Reply 128
Original post by otrivine
Kevlar = is a polyamide and undergoes Condensation polymerisation.

The reactants involved are:-

Benzene-1,4-diamine + Benzene-1,4-dicarboxylic acid

As a result of condensation(removal of water) the two compounds join together to form a long repeat unit and forms kevlar used in bulletproof vests for example.


Yep and the formula for the amount of water produced for n reactants is
2(n-1) :biggrin: WELL DONE
Reply 129
Original post by otrivine
Kevlar = is a polyamide and undergoes Condensation polymerisation.

The reactants involved are:-

Benzene-1,4-diamine + Benzene-1,4-dicarboxylic acid

As a result of condensation(removal of water) the two compounds join together to form a long repeat unit and forms kevlar used in bulletproof vests for example.


Can I ask for your advice please :wink: before we continue revision.
Reply 130
Original post by Gulzar
Yep and the formula for the amount of water produced for n reactants is
2(n-1) :biggrin: WELL DONE


Yes , I did not get that formula? how do we use it?

Thanks for reminding me about that!

Define: esterification
Reply 131
Original post by Gulzar
Can I ask for your advice please :wink: before we continue revision.


of course ! :smile:
Reply 132
Original post by otrivine
of course ! :smile:


I have 246 UMS in my AS chemistry...so 6 up off the A grade.
Im not doing too well in my practicals for A2 :frown:
Do u think I have a chance of getting the A grade in the summer.
Im ressitting f324 (got a U) and taking f325 as well.
Reply 133
Original post by Gulzar
I have 246 UMS in my AS chemistry...so 6 up off the A grade.
Im not doing too well in my practicals for A2 :frown:
Do u think I have a chance of getting the A grade in the summer.
Im ressitting f324 (got a U) and taking f325 as well.


What do you have for your practicals so far?

What is your total UMS for AS+practical for A2?
Reply 134
Original post by otrivine
What do you have for your practicals so far?

What is your total UMS for AS+practical for A2?


qual- 7/10
quant 14/15
eval 7-15 (retaking...its electrode potentials next week :O
Reply 135
Original post by Gulzar
qual- 7/10
quant 14/15
eval 7-15 (retaking...its electrode potentials next week :O


lets say 35ums you have for your A2 practicals with these marks.

so

246+35= 281 ums

so you currently hold 281ums and you would need an extra 199 UMS marks to get an A, essentially, if you have to get high A in both F325 and F324 to get an A! My suggestion, is try to push the evalutative to 15/15 and then you would only need to get an A on one paper and a B on the other.
Reply 136
Original post by otrivine
lets say 35ums you have for your A2 practicals with these marks.

so

246+35= 281 ums

so you currently hold 281ums and you would need an extra 199 UMS marks to get an A, essentially, if you have to get high A in both F325 and F324 to get an A! My suggestion, is try to push the evalutative to 15/15 and then you would only need to get an A on one paper and a B on the other.


Oh I wish I could get 15/15 :frown:
Ok thanks, Ill try.
esterification is when an alcohol reacts with a carboxylic acid to produce an ester...with the elimination of a water molecule for every 1:1 ratio of alcohol and carboxylic acid reacting.
Reply 137
Original post by Gulzar
Oh I wish I could get 15/15 :frown:
Ok thanks, Ill try.
esterification is when an alcohol reacts with a carboxylic acid to produce an ester...with the elimination of a water molecule for every 1:1 ratio of alcohol and carboxylic acid reacting.


I am sure you will do it! Keep at it, I wish I could help but I did all my practicals last year so they changed it this year.:frown:

Correct, my turn
Reply 138
Original post by otrivine
I am sure you will do it! Keep at it, I wish I could help but I did all my practicals last year so they changed it this year.:frown:

Correct, my turn


State what molecular conditions are needed for a molecule to hold a stereoisomeric property?

Btw will it be too hard to get high A's in both papers?
Reply 139
Original post by Gulzar
State what molecular conditions are needed for a molecule to hold a stereoisomeric property?

Btw will it be too hard to get high A's in both papers?


is it that there should be restricted rotation of (around) the carbon -carbon double bond and that each carbon atom must be attached to four different atoms or groups of atom, also a double bond must be present. Also, there are two types of stereoisomers , E-Z (cis/trans).


I dont think it should be hard, but you have to work hard. This is all subject to difficulty of paper.