[arvin_infinity]

It would be much appreciated if someone check whether the following is right or not

octahedral = 6 ligands (90 degree bond angles)
tetrahedral = 4 ligands (109.5 degree bond angles)
square planar = 4 ligands, (also 90 degree bond angles)
I guess that's all we need to know for A2

Also if anyone has a good trick/method to remember this


+rep

[Smiley Face :)]

[QUOTE=arvin_infinity;37445193]It would be much appreciated if someone check whether the following is right or not

octahedral = 6 ligands (90 degree bond angles)
tetrahedral = 4 ligands (109.5 degree bond angles)
square planar = 4 ligands, (also 90 degree bond angles)
I guess that's all we need to know for A2


Also if anyone has a good trick/method to remember this


+rep[/QUOTE

um its pretty much that... Square planar (only one to remember for A2 is cisplatin)
If u draw the 3d diagrams for the complex ions its pretty evident that the bond angle has to be 90 for an octrahedral...
Unfortunately you just have to remember these!!

[charco]

(Original post by arvin_infinity)
It would be much appreciated if someone check whether the following is right or not

octahedral = 6 ligands (90 degree bond angles)
tetrahedral = 4 ligands (109.5 degree bond angles)
square planar = 4 ligands, (also 90 degree bond angles)
I guess that's all we need to know for A2

Also if anyone has a good trick/method to remember this


+rep

I've seen some (stupidly) rigorous mark schemes that have insisted on 90º AND 180º for octahedral ...

... but, like I say, it's pretty daft.

[arvin_infinity]

[QUOTE=Smiley Face


If u draw the 3d diagrams for the complex ions its pretty evident that the bond angle has to be 90 for an octrahedral... [/QUOTE]

+rep
That actually did help - although I didn't draw it I visualised it

[Smiley Face :)]

(Original post by arvin_infinity)
+rep
That actually did help - although I didn't draw it I visualised it

Cool

[arvin_infinity]

(Original post by charco)
I've seen some (stupidly) rigorous mark schemes that have insisted on 90º AND 180º for octahedral ...

... but, like I say, it's pretty daft.

Didn't get that!
180?

[charco]

(Original post by arvin_infinity)
Didn't get that!
180?

like the two axial sites (for example)

[Smiley Face :)]

(Original post by charco)
like the two axial sites (for example)

Basically from the bottom to the top
So imagine a graph goinng from -10 to 10 on the y axis is 180 degs

[arvin_infinity]

(Original post by charco)
like the two axial sites (for example)

Oh I thought we never measure that angle between bonds far apart!! interesting!

So does that mean for other molecules ,say, H20 there is another angle as well (I mean an angle in addition to 104.5) you know like 255.5! (360-104.5)

[charco]

(Original post by arvin_infinity)
Oh I thought we never measure that angle between bonds far apart!! interesting!

So does that mean for other molecules ,say, H20 there is another angle as well (I mean an angle in addition to 109.5) you know like 255.5! (360-109.5)

Like I said, I've only ever seen it in a mark scheme for octahedral ... and, I repeat, it doesn't make sense.

[arvin_infinity]

(Original post by charco)
Like I said, I've only ever seen it in a mark scheme for octahedral ... and, I repeat, it doesn't make sense.

In post above I meant to say 104.5 and 255.5...

well I guess I can deal with one additional number-180

aand wondered if thats Edexcel you are talking about .