AS Chemistry- helping each other out!

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Reply 140

ainura.km

Hello

I'm also doing AS Chemistry (edexcel) :smile:

Such an awesome idea to gather AS chem students and help each other out!

Reply 141

l1lvink

Original post by charco

E/Z is a more complete way of designating stereoisomers as it can be used for unsaturated compounds that don't have two groups the same. eg FClC=CBrI

Cis-trans description requires that at least two of the groups attached to the double bond are identical.

Ah, that explains why there are 2 ways of explaining what I thought were the same thing.
Will have to ask my Chemistry teacher if I need to know the difference.

Reply 142

lyricalvibe

Original post by zhang-liao

Sorry bout the late reply, went to sleep :colondollar:

They open all their taster courses on the 11th of January I believe

Haha, understandable :smile:

Ahh k, which you doing?

Original post by noshahmad

Doing all 4 will be difficult. I guess they do all compliment each other so you can talk about it vaguely but still having some sort of focus. I just checked and it said the deadline is in March for those in London?

Posted from TSR Mobile

You started yours yet? I'm starting mine now...
I looked it up and it varies by region, for some reason essex-my whereabouts- is one of the first with mid January :unimpressed:

sorry for the misinformation :redface:

Reply 143

lolly786786

12 What is the total number of atoms in 1.8 g of water, H2O?
DATA
The molar mass of H2O is 18 g mol–1
The Avogadro Constant is 6.0 × 1023 mol–1
A 6.0 × 1022
B 6.0 × 1023
C 1.8 × 1023
D 1.8 × 1024

Guys, i understand that these kinda questions are pretty basic, but if someone could help me out by teaching me how to work this out that would be great :smile:

Reply 144

danconway

Original post by lolly786786

12 What is the total number of atoms in 1.8 g of water, H₂O?

DATA
The molar mass of H₂O is 18 g mol^–1
The Avogadro Constant is 6.0 × 10²³ mol^–1

A 6.0 × 10²²
B 6.0 × 10²³
C 1.8 × 10²³
D 1.8 × 10²⁴

Guys, i understand that these kinda questions are pretty basic, but if someone could help me out by teaching me how to work this out that would be great :smile:

The Avogadro Constant (N_A) is number of particles of a substance (atoms, molecules, ions) in one mole of the substance.

So, first, you need to work out how many moles of water there are, and then multiply that by N_A for the number of molecules of water (because you used the number of moles of H₂O, which is a molecule, you'll get the number of molecules out).

Then have a think about how you get from molecules to atoms.

(edited 9 years ago)

Reply 145

Feraligatr

Original post by lyricalvibe

Haha, understandable :smile:

Ahh k, which you doing?

You started yours yet? I'm starting mine now...
I looked it up and it varies by region, for some reason essex-my whereabouts- is one of the first with mid January :unimpressed:

sorry for the misinformation :redface:

I'm hoping to do a Chemistry taster course :tongue:

BTW - If you live on border line of Essex/London, they might just change it. My school is under London but also Essex so they changed the deadline

Reply 146

Feraligatr

I've created a document showing some insoluble and soluble compounds

According to what I've seen in Edexcel past papers (at least) you sometimes get questions asking you on specific insoluble and soluble compounds which some candidates don't know of or unaware of.

Just thought I'd share :colondollar:

Soluble.docx13.2KB

Reply 147

zara1234567

Original post by BCMFM16

I'm taking Biology, Chemistry, Maths and French. I'm thinking of dropping Maths for A2. Also i do the EPQ which our entire year were made to do. :confused:

Heeeey how come I haven't been able to private message you anymore?? I actually tried alot but randomnly stopped. I'm doing Chemistry and Biology too how are you finding it? :colondollar:

Reply 148

BCMFM16

Original post by zara1234567

Heeeey how come I haven't been able to private message you anymore?? I actually tried alot but randomnly stopped. I'm doing Chemistry and Biology too how are you finding it? :colondollar:

Doesn't it work?! Let me see to that! Biology causes me lots of stress i've predicted a C so far anyway. Chemistry is good i'm predicted a B but i hear unit 2 is horrible... :eek:

Reply 149

zara1234567

Has anyone done the Chemistry isa yet or started it? I've only done the quantitative so far and if anyone needs help on that paper feel free to private message me for some general tips you need to revise for it

Reply 150

zara1234567

Original post by BCMFM16

Doesn't it work?! Let me see to that! Biology causes me lots of stress i've predicted a C so far anyway. Chemistry is good i'm predicted a B but i hear unit 2 is horrible... :eek:

Yeah it doesn't since like aaaages ago at least 4 months since you helped me out on Biology GCSE. Aww hahaha my predictions are abit similar. Have you done any courseworks yet how have you been

Reply 151

Feraligatr

Original post by zara1234567

Note that you can't share papers on TSR, against the rules. Just saying..

Reply 152

zara1234567

Yeah yeah dw I don't share papers haha. I meant just tips for it you know general like for titrations....

Reply 153

BCMFM16

Original post by zara1234567

Yeah it doesn't since like aaaages ago at least 4 months since you helped me out on Biology GCSE. Aww hahaha my predictions are abit similar. Have you done any courseworks yet how have you been

Oh I remember you! In Biology i've done 2 so far. You get 3 attempts at each one. On my first one I got 6/10 on the first section... :eek:

I need another attempt at that... :rolleyes:

Reply 154

zara1234567

Aha yeah. oooh as if. That's good though 6/10 you know. Also do you know why I can't private message you still.

It says 'BCMFM16 has chosen not to receive private messages or may not be allowed to receive private messages. Therefore you may not send your message to him/her.'