[elfishies]

Hi, I've been trying to solve this question but I'm having some trouble:

For the molecular structure of ketoisophorone
( http://www.tcichemicals.com/image/commodity/K0034.gif )


a)How many σ-bonds are there in the molecule?

-I counted 22 but it was wrong. I know that there's 1 sigma bond in a single bond, 1 in double & 1 in triple but I still can't seem to get the answer right

b)How many pairs of non-bonding electrons are there in the molecule?

-I'm thinking that you'll have to add the number of electrons C(9x4)+H(12x1)+O(2x6)=60 and then subtract 2x(# of bonds formed)? but since i'm getting the number of sigma bonds wrong, I'm not sure how many bonds are formed.

It would be great if you could explain and *delete me*

[thetada]

I get 23. Did you count the single hydrogen atom between the top right methyl group and the bottom carbonyl group?

[elfishies]

The answer 23 is correct! Thank you so much, and you were right I did miss that one.

[thetada]

No worries :-)