How can you tell what shape a molecule is going to be?

The key to determining the shapes of molecules is to think about number of lone and bonded pairs of elections and the interactions between these pairs. In doing this we apply the valence-shell election-pair repulsion (VSEPR) theory. In summary, this theory states that all electron pairs repel each other, so spread as far away from each other as possible to minimise repulsions. 

The other point to consider is the strength of these repulsions, lone pair-lone pair repulsions are the strongest, followed by lone pair-bonded pair and bonded pair-bonded pair is the weakest. So by counted the number of bonded and lone pairs of electrons we can figure out what shape a molecule is going to be. (After and during this I would demonstrate with a few example diagrams and then some questions to check understanding).

AM
Answered by Anna M. Chemistry tutor

1896 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

What is hybridisation and how can it be used to explain the shapes of molecules?


How does aromatic electrophilic substitution work?


Explain why: a) Fluorine is more electronegative than chlorine b)∆H hydration fluoride is more negative than ∆H hydration chloride


Name and draw the mechanism by which benzene reacts with ethanoyl chloride in the presence of a catalyst. Also explain why benzene undergoes a substitution reaction, rather than an addition reaction.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences