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Aqa chem 4/ chem 5 june 2016 thread

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Reply 2080
Original post by YoloSwagginz
http://m.imgur.com/ulgdobg

It's yellow and the exams consider them yellow check 2013 or the 2014 pap


yeah thanks, just more confusion from my side lol ive deleted that comment.
Can someone please explain when al(oh)6 3- is formed? All my notes say al(oh)4- but the mark scheme for Jan 2011 says Al(oh)6 3-.
Hey guys, not sure if we need to know this but I'm curious anyways:

It says the units for planck's constant are J s what does the 's' stand for?
reading the textbook about how exothermic reactions can be spontaneous and its talking about the decrease of energy in the system allows an increase the entropy of the surroundings.... we don't need to know this much detail do we? I've never seen it come up
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Original post by AL20xxx
Can someone please explain when al(oh)6 3- is formed? All my notes say al(oh)4- but the mark scheme for Jan 2011 says Al(oh)6 3-.


Sure

Ligands that are similar sizes have the same coordination number so

Nh3 oh h2o and cn as Ligands will all form al(c)6

Where cl- ions will form al(cl)4 due to it being considered "larger" think it may have to do with it having a larger charge cloud but idk cause we don't need to know its theory
when asked to draw a complex do we do arrows to the ligand or do the dotted lines/triangles to show the shape???
Reply 2086
Original post by lahigueraxxx
Hey guys, not sure if we need to know this but I'm curious anyways:

It says the units for planck's constant are J s what does the 's' stand for?


seconds
Original post by thomaarrss
when asked to draw a complex do we do arrows to the ligand or do the dotted lines/triangles to show the shape???

Dotted / arrows
Original post by Jmedi
seconds


cheers! :smile:
Is [co(nh3)6]3+ dark brown or yellow??
Reply 2090
Original post by olivia7001
Is [co(nh3)6]3+ dark brown or yellow??


brown
Original post by olivia7001
Is [co(nh3)6]3+ dark brown or yellow??


You don't need to know that

Check specification page 60

Only complex ion with nh3 you need to know is cu(nh3)4(h2o)2

Which is deep blue
(edited 7 years ago)
Reply 2092
Original post by olivia7001
Is [co(nh3)6]3+ dark brown or yellow??


dark brown. its the 2+ that is pale yellow or pale brown. if left to air or reacted with h202 the 2+ complex is oxidised to 3+
Reply 2093
think i've memorised all the necessary colours now, thanks all!


Thank you!yeahh, I just did this right now! Apparently there's a quicker way but I like this way much more
Much appreciated!



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Original post by YoloSwagginz
You don't need to know that

Check specification page 60

Only complex ion with nh3 you need to know is cu(nh3)4(h2o)2

Which is deep blue


You do need to know that :/




Posted from TSR Mobile
Original post by olivia7001
Is [co(nh3)6]3+ dark brown or yellow??


Dark brown

[Co(NH3)6]2+ is yellow
Someone correct me if I'm wrong


Posted from TSR Mobile
Original post by olivia7001
Is [co(nh3)6]3+ dark brown or yellow??


2+ is straw coloured and it darkens in air. So brown
Do all-nighters actually work for people?? Has it worked for you in the past??
Original post by Bloom77
You do need to know that :/




Posted from TSR Mobile



http://m.imgur.com/AauQULW

Spec disagrees with you bud, but I guess we can just waste time memorizing stuff we don't need to know.

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