Colour of [Cu(H2O)6]^2+

violet

Is the colour of this complex blue, or pale blue, or green?
It calls it all 3 in my text book and revision guide.. :confused:

mine says blue

which makes sense cuz copper (II) sulphate is blue

Reply 2

Revenged

mine says blue

which makes sense cuz copper (II) sulphate is blue

[Cu(H20)4(NH3)2]²⁺ is deep blue, which is probably why they called [Cu(H20)6]²⁺ pale blue

Reply 3

violet

OP

Revenged

[Cu(H20)4(NH3)2]²⁺ is deep blue, which is probably why they called [Cu(H20)6]²⁺ pale blue

Yep, probably!
Thanks, my text book and revision guide have so many mistakes! :mad:

Reply 4

Magician

violet

Yep, probably!
Thanks, my text book and revision guide have so many mistakes! :mad:

oui, mine says pale blue aussi

Reply 5

violet

OP

Mathemagician

oui, mine says pale blue aussi

Merci

Reply 6

violet

Yep, probably!
Thanks, my text book and revision guide have so many mistakes! :mad:

It may appear all three (not at one though!) depending on the conditons, for the purpose of the exam i'd advise you to look at the User guide if you do Edexcel Chemistry.

Reply 7

john !!

14

light blue is correct.. on a similar subject, could anyone give me the perfect exam answer to this?

explain how the colour in this complex ion arises (for 3 marks)
cheers..

Reply 8

kpg

11

This isnt the model answer by any means but

Light shines on the solution
Splits the d orbitals into two - with different energy levels
As light is absorbed, an electron is promoted to the higher energy level

Reply 9

kpg

This isnt the model answer by any means but

Light shines on the solution
Splits the d orbitals into two - with different energy levels
As light is absorbed, an electron is promoted to the higher energy level

the frequency of light removed from the reflected light is that responsible for the transiotion.

the light shone is VISIBLE WHITE light.

Reply 10

The colour that is complimentary to the light absorbed is seen... right?

Reply 11

Revenged

The colour that is complimentary to the light absorbed is seen... right?

Might you rephrase that please. Probably my fault, but i didnt quite make sense of tht.

sorry.

Reply 12

No problem...

i learnt that if say blue light is absorbed it is the complimentary colour that is seen

complimenatary colour = colour that is opposite in a colour wheel

well, basically, it's NOT the wavelength of light absorbed that you see - it's the one that is reflected, that's all i was checking

Reply 13

violet

OP

Yep, that's how i learnt it too. With the pretty colour wheel!

Reply 14

Revenged

No problem...

i learnt that if say blue light is absorbed it is the complimentary colour that is seen

complimenatary colour = colour that is opposite in a colour wheel

well, basically, it's NOT the wavelength of light absorbed that you see - it's the one that is reflected, that's all i was checking

Yes that absouloutely correct!

Thanks

Reply 15

kpg

11

AtSnIaB-42

the frequency of light removed from the reflected light is that responsible for the transiotion.

the light shone is VISIBLE WHITE light.

Yes, I was in a rush so didnt really complete the answer but you're right.

However, having gone through the past papers though you don't need to go into anywhere near the detail the textbook goes into. 3 marks seem to be awarded for

d-orbitals split;
electron promoted from lower energy level to higher energy level;
light from visible region is absorbed

Seems pretty fair/generous.

Reply 16

kpg

Yes, I was in a rush so didnt really complete the answer but you're right.

However, having gone through the past papers though you don't need to go into anywhere near the detail the textbook goes into. 3 marks seem to be awarded for

d-orbitals split;
electron promoted from lower energy level to higher energy level;
light from visible region is absorbed

Seems pretty fair/generous.

Granted. I brought a bit of Quantum threory into it. I hoped it would clarify it a little more. But you've got the key points well sussed.

Reply 17

wednesburywench