Higher chemistry 2014-2015

Scroll to see replies

There was a fair bit of higher chem in AH bio, and a significant amount of higher physics in AH chem.

I'd more say chem is for physics people who are weak mathematicians...

Posted from TSR Mobile

I'd say chem is a good balance of biology and physics. maths doesnt really come into it much for me cause I can handle the maths in physics/chemistry

Reply 741

username1405872

Original post by chopinfan

Sulphuric acid is what we call a 'diprotic' acid - it contains two hydrogen atoms. This means that it produces twice as many hydrogen ions, so the volume of gas produced is doubled and the reaction is quicker as there is a higher concentration of H+ ions :smile:

Posted from TSR Mobile

ok thanks

I totally get it now I just didn't see it earlier on. Altho in cfe higher there is no mention of protic and diprotic which is why I didn't quite get it. Its amazing the number of ppl who are still doing the old higher. To me it seems judging by these threads that there is more old higher ppl than new cfe!! But good luck in both guys!!

Reply 742

VividBandicoot

Original post by HiddenNinja01

Can anyone explain how this can be done?

This got answered a bit back mate. Go take a look.

Reply 743

VividBandicoot

I'm giving up now, hopefully it all goes good tomorrow. Good luck to you all! Its weirdly been great fun procrastinating with you guys on here and getting and giving help from and to you guys! See you all after the summer on the AH thread :wink:

Reply 744

HiddenNinja01

Original post by Zain-A

This got answered a bit back mate. Go take a look.

Thanks, Also best of luck to you aswell and everyone else!

Reply 745

username1921763

Good luck to everyone!

Reply 746

HiddenNinja01

Original post by Zain-A

This got answered a bit back mate. Go take a look.

Around how far back btw...i cant find it lol

Reply 747

Hejhej

I know it's a bit late but I am finding redox reactions a bit difficult, any quick or easy way to understand redox reactions a bit better would be very much appreciated. Thanks

Reply 748

HiddenNinja01

Guys will i still get full marks for a calculation question if i had the correct answer and some sort of working during how i obtained it?
Since i dont do it like the marking scheme.
Thanks
For example electrolysis questions, i do them a little different

(edited 8 years ago)

Reply 749

HiddenNinja01

Original post by Hejhej

I know it's a bit late but I am finding redox reactions a bit difficult, any quick or easy way to understand redox reactions a bit better would be very much appreciated. Thanks

Check the previous couple pages, Junioh posted some helpful video links on the topic

Reply 750

Hejhej

Original post by HiddenNinja01

Check the previous couple pages, Junioh posted some helpful video links on the topic

Thanks a lot

Reply 751

chopinfan

Good luck everyone!! See some of you on the next AH thread (got to do well in this first though :erm:

)

Don't think my brain could take any more cramming lol

Posted from TSR Mobile

Reply 752

GrappleX

Original post by Zain-A

In higher biology, there is zero chem, lol it's all just data interpretation.

So damn true! Some papers, for A Levels are almost all Data analysis 😂

Posted from TSR Mobile

Reply 753

HiddenNinja01

Can someone help do this and tell me how you would do it? thanks so much!

Reply 754

BCEHM

Original post by HiddenNinja01

Can someone help do this and tell me how you would do it? thanks so much!

So you would look on page 9 of the data booklet for the enthalpies of combustion of these substances
Hydrogen is -286 kJ
Carbon is -394 kJ but we have 2 mol of carbon so 2 x -394 kJ = -788 kJ
Ethyne is -1300 kJ but since this is on the other side of the equation we reverse it so it become +1300 kJ

Then we add the all together to get +226 kJ and that is your final answer!
Hope this helped

Reply 755

username1283138

Good luck to you all!!! :smile:

Reply 756

Ed2015

Good luck everyone thank you so much for all the help :biggrin:

Posted from TSR Mobile

Reply 757

Stone101

Does anyone know why the answer to this is C? I would have thought it would be C and D

image.jpg518.7KB

Reply 758

Yammy

Original post by Stone101

Does anyone know why the answer to this is C? I would have thought it would be C and D

Non polar bonds have same electronegativity values, so Hydrogen is 2.2 so only another atom with 2.2 can bond to it without making the bond polar :biggrin:

Reply 759

gwagon

Original post by HiddenNinja01

Around how far back btw...i cant find it lol

They said alkane. So immediately in your mind you want to find an alkane with a RAM close/equivalent to that of ethane 1.2 diol or whatever they mentioned.
Butane is the closest.