Ab3e3

What would be a good molecule to use as an example of AB3E3? Many thanks!

First of all, what do you mean by AB3E3, are a,b and e meant to be elements?

VSEPR Classification - A central atom, B number of bonds (double doubles count as just 1), E number of lone pairs.

Such as CO2 = AB2
or H2O = AB2E2

So AB3E3 would be an element/ion with three bonds and three lone pairs on the central atom, I just can't think of a good example that actually exists.

VSEPR Classification - A central atom, B number of bonds (double doubles count as just 1), E number of lone pairs.

Such as CO2 = AB2
or H2O = AB2E2

So AB3E3 would be an element/ion with three bonds and three lone pairs on the central atom, I just can't think of a good example that actually exists.

You do mean an element with three bonds = 6 electrons(probably less if it is dative covalent instead), three lone pairs = 6 valence electrons, but we only have up to group VIII. Hmm, seriously, i have not used this sort of VSEPR classification before.

I don't think it can actually exist. 3 lone pairs means 6 electrons. + 3 bonds means that the outer shell will have at least 6 more electrons.

Expanded octet, elements in period 3 or below can show hypervalency (expanded octet) where they have more then 8 electrons around them. For example, SF6 exists due to an expanded octet on the S - it has 12 electrons around it.

Hmm, that is true though.

I thought of something like [XeF3]- where xenon donates three electrons into the bond, its a minus charge so it leaves 6 (3 lone pairs) around xenon making it AB3E3 but I don't even know if that can exist.

So far I have:

AB6 - SF6
AB5E - BrF5
AB42 - XeF4

Which I know are correct after talking with a lecturer.

The way the question is worded is 'might be an example of AB3E3' so I may just go with the [XeF3]- even though it may not exist in reality.

The [XeF3]- seems unlikely, isn't it, because the xenon is usually favoured in the square planar structure, removing one of the fluorine would destablize the whole struture, won't it? not too sure about this either. What year are you in uni anyway?

I think xenon triflouride can exist actually

Maybe Xenon diflouride, but I'm not too sure about triflouride.

Maybe you misread the question?

hmm feels like a typo to me, having had a good look through a number of textbooks I couldn't find a single example...

Thanks for taking the time to look, appreciate it It could be a typo, won't get the result for it until monday so will have to wait and see.