chemistry mcq on bond angles help needed

[angelgurl]

 

[angelgurl]

can somebody tell me which angles 1 2 and 3 are
im really confused abt angle 2

 

[aquariangurl]

It's B isn't it?

 

[angelgurl]

no the marking scheme says its C!!!
nov 2010 paper 11 question 7
and plz explain need ur help!!

 

[hassam]

1=109.5 2=120 3=104.5

 

[angelgurl]

hey do we consider the double bond as a single one? the C=O bond in 2 because only then we get 120?
just want to confirm this

 

[Zenzenzen]

hey do we consider the double bond as a single one? the C=O bond in 2 because only then we get 120?
just want to confirm this

Yes! the double bond is considered as a single bond

For example:
X=Y=X
X-Y-X

They both have a bond angle of 180 degrees

 

[angelgurl]

thanks!!!
do you think we can get a question on sp2 sp and sp3 hybridisation in mcq paper?

 

[aquariangurl]

Yes we can, although it's kinda rare

 

[angelgurl]

and can we get some qs on benzene compounds because i have seen them in some years though they involve AS organic but theyre complex enough!

 

[MHHaider707]

yeah we can also have Qs abt benzene ring!!

 

[aquariangurl]

In AS we have to know about the structure of benzene only, so in that case yes, we will get qs on benzene!

 

[hassam]

i never saw any hybridisation question in mcqs though its nt dat hard

 

[angelgurl]

ive seen hybridisation ones just in the early papers somewhere between june 2002 to 2004

 

[Flash667]

1 = 109.5 degree, 4 bonds making a tetrahedral shape
2 = 120 degree, 3 bonds giving a trigonal planar shape
3 = 105 degree, 2 bonds & 2 lone pairs of Oxygen atom giving a tetrahedral shape... The reason bond 1 & 3 are same because repulsion between a bond & bond and repulsion between bond & lonepair ain't the same, the latter force of repulsion is a bit more. :Yahoo!: Hope u got the hang of it man... --Peace--