Edexcel A2 Chemistry Exams -6CH04 (14th June) and 6CH05 (22nd June) Discussion Thread

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Could someone please explain how to do 24di,ei and f please :/ So confused
-thanks

Not too sure about part ei unfortunately.

However, for part fi), I would think back to unit 4...a certain reaction involving electrophilic addition?? Ring any bells?

Reply 221

Ayman!

15

Original post by samb1234

Yeah unit 5 has way way too much content in it unfortunately, i've literally spent like 75% of the last week or so just on unit 5 so hopefully will be fine but gonna need to shift my priorities a bit I think lol. What are you doing at uni? Some form of engineering/physics type thing i'm guessing

Haha, at least you've spent some time on it - I have a lot to do. xD If I get about 86 on FP2 I should have the A* so I'll basically be done worrying about maths.

Yep, engineering. Thermodynamics and kinetics I'll still need. The organic stuff, not so much

Reply 222

ST_123

5

Original post by Don Pedro K.

Not too sure about part ei unfortunately.

However, for part fi), I would think back to unit 4...a certain reaction involving electrophilic addition?? Ring any bells?

So for d) i have that its a 2:1 ratio and i know that adding hydrogen to an alkene forms an alkane, i just don't get how that first bit of information links to the second bit

For fi i totally misread the question and thought it was trying to link to the previous parts >.<. I guess the nucleophilic addition of hydrogen cyanide will suffice for this question.

Reply 223

Don Pedro K.

9

Original post by ST_123

So for d) i have that its a 2:1 ratio and i know that adding hydrogen to an alkene forms an alkane, i just don't get how that first bit of information links to the second bit

For fi i totally misread the question and thought it was trying to link to the previous parts >.<. I guess the nucleophilic addition of hydrogen cyanide will suffice for this question.

Yep, 2:1 ratio for hydrogen gas: carvone is correct. Now look at carvone; it's got two C=C double bonds. What do you think is going to happen when it's reacted with hydrogen gas then?

Reply 224

ST_123

5

Original post by Don Pedro K.

Yep, 2:1 ratio for hydrogen gas: carvone is correct. Now look at carvone; it's got two C=C double bonds. What do you think is going to happen when it's reacted with hydrogen gas then?

Ah they booth break. I get it now, thank you!
Out of curiosity what would happen if the ratio changed to 3:1 for example?

Reply 225

Don Pedro K.

9

Original post by ST_123

Ah they booth break. I get it now, thank you!
Out of curiosity what would happen if the ratio changed to 3:1 for example?

Hmm well I don't think anything would change since there are only two double bonds. Not 100% sure though, sorry xD

Reply 226

samb1234

OP

13

Original post by Ayman!

Haha, at least you've spent some time on it - I have a lot to do. xD If I get about 86 on FP2 I should have the A* so I'll basically be done worrying about maths.

Yep, engineering. Thermodynamics and kinetics I'll still need. The organic stuff, not so much

Ah nice, any specific branch of engineering?

Reply 227

Don Pedro K.

9

@samb1234 Do you know any of the potential error sources which prevent fuel-cell breath analysers' data being used in court?

Reply 228

samb1234

OP

13

Original post by Don Pedro K.

@samb1234 Do you know any of the potential error sources which prevent fuel-cell breath analysers' data being used in court?

They can give false readings if you have drunk a very short period of time before the test, there can be calibration errors (although the machine used in police stations takes two separate readings to avoid this), makes assumptions about the ratio of alcohol in the breath to blood etc etc

Reply 229

lordoftheties

13

Guys why are some of the metals 1 mark and the others full marks for this question?

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Reply 230

Don Pedro K.

9

Original post by lordoftheties

Guys why are some of the metals 1 mark and the others full marks for this question?

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This was something that also confused me when I did this question. Maybe @samb1234 knows?

Reply 231

Funky_Giraffe

10

Original post by lordoftheties

Guys why are some of the metals 1 mark and the others full marks for this question?

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Original post by Don Pedro K.

This was something that also confused me when I did this question. Maybe @samb1234 knows?

Well for the first 3, think about what how vigorously group 1 metals react with water, and how practical (or not!) that might be in this situation... :smile:

Reply 232

Don Pedro K.

9

Original post by Funky_Giraffe

Well for the first 3, think about what how vigorously group 1 metals react with water, and how practical (or not!) that might be in this situation... :smile:

Ahhh yes, explosions. Hahaha xD

By the way, what colour are Fe2+ and Fe3+ in solution? I seem to be finding mixed answers :s