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bond angles

hi
basically i know all the bond angles but am confused when they say work out bond angle for COH or something...which bond do i look at?

Reply 1

member169510

I always think, if there are 4 bonded pairs with no lone pairs then the angle is 109deg. Then for every bonded pair you take off and lone pair you put on you take off 2.5deg. So water with two bonded pairs and two lone pairs has a bond angle of 104deg.
If that makes sense :s-smilie:

Reply 2

Languages Nutter

El-Taji

hi
basically i know all the bond angles but am confused when they say work out bond angle for COH or something...which bond do i look at?

Unless I've missed something, COH couldn't exist as a molecule: it would need an extra hydrogen atom and be CHOH - methanal.

Since methanal looks like that, the bond angle is invariable as there are three regions of electron density. Therefore the overall bond shape is trigonal planar and the bond angle is consequently 120 degrees.

Hope this helps - sorry if I've got the wrong end of the stick!

Reply 3

El-Taji

thansk for both responses but what i meant was when you are given a compound e.g. propan1ol and they ask your for the COH bond angle!! i think i get it now tho
thanks anyway

Reply 4