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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: surfgrinder11 on March 22, 2008, 12:10:21 PM

Title: molecular geometry
Post by: surfgrinder11 on March 22, 2008, 12:10:21 PM

What is the molecular geometry if you have a double bond, a single bond and 1 lone pair around the central atom?

Linear
tetrahedral
bent with bond angle around 118 degrees
pyramidal
bent with bond angle around 107 degrees

Title: Re: molecular geometry
Post by: Dan on March 22, 2008, 12:19:54 PM

Read up on VSEPR theory (http://www.google.co.uk/search?sourceid=navclient&aq=t&ie=UTF-8&rls=GGLJ,GGLJ:2006-34,GGLJ:en&q=VSEPR)

Title: Re: molecular geometry
Post by: Alpha-Omega on March 22, 2008, 04:49:30 PM

According to VSEPR that type of molecule would have the designation AX2E1.  Where the central atom is designated as A, the two bonded species are X (X2), and the lone pair on the central atom is E1. 

Examples of molecules like this are NO₂^-, SO₂ (specific to your designation), and O₃.

They are Bent, the bond angle between the S and O is actually somewhat less than the predicted.theoretical 120^o.  It is compressed to approximately 118^o due to the presence of the lone pair on the central S atom.

See the diagrams and explanation regarding VSEPR in the reference cited below:
 
http://butane.chem.uiuc.edu/cyerkes/Chem102AEFa07/Lecture_Notes_102/newLecture%2014-102.htm

Title: Re: molecular geometry
Post by: surfgrinder11 on March 22, 2008, 05:26:10 PM

Thank You