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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: ajax0604 on January 24, 2012, 10:21:53 PM

Title: why does sulfur element exist as S8 but oxygen exists as a diatomic molecule?
Post by: ajax0604 on January 24, 2012, 10:21:53 PM
They belong to the same group so wouldn't they bond in a similar way?
Title: Re: why does sulfur element exist as S8 but oxygen exists as a diatomic molecule?
Post by: sjb on January 25, 2012, 02:25:32 AM
Quote from: ajax0604 on January 24, 2012, 10:21:53 PM
They belong to the same group so wouldn't they bond in a similar way?

What is the bond strength for O=O, O-O, S=S, and S-S? Consider also N2 and P4, for instance.
Title: Re: why does sulfur element exist as S8 but oxygen exists as a diatomic molecule?
Post by: ajax0604 on January 26, 2012, 12:45:09 AM
I've looked up the bond energies on this website http://www.wiredchemist.com/chemistry/data/bond-energies-lengths but I'm still not seeing the connection between bond energies and why S8 forms in preference to S2.
Title: Re: why does sulfur element exist as S8 but oxygen exists as a diatomic molecule?
Post by: UG on January 26, 2012, 01:04:02 AM
Consider the number of S-S bonds in S8, how much energy is released when a molecule of S8 forms? Next consider the formation of four S2 molecules which are double bonded, how much energy is released in this process?