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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: peacefulltortoise on December 28, 2005, 06:32:06 AM

Title: HOCl structure
Post by: peacefulltortoise on December 28, 2005, 06:32:06 AM

I see that HOCl has V-sharp and its structure is H - O - Cl, therefore we just care of O as centre atom. However some books show that this molecule is AX2E3 type (follow VSEPR) so Cl is centre atom and it has 2 bond pairs, 3 lone pairs. Could anyone tell me why?

Title: Re:HOCl structure
Post by: lemonoman on December 28, 2005, 08:15:40 AM

I remember in my early early days of drawing lewis structures that they always said, "Put the heaviest atom at the centre" - this works well for metallocentred molecules and even for simple p-block compounds like SF₆.  But of course, that rules doesn't always apply, and can lead to poor point-group assignment.

Perhaps this is the problem?

Title: Re:HOCl structure
Post by: peacefulltortoise on December 29, 2005, 05:18:23 AM

So at last which one is correct?

Title: Re:HOCl structure
Post by: Albert on December 29, 2005, 06:22:53 AM

I had never seen lemonoman's structure, while I've always thought the former (looking at your post) to be the right one. So, that would be my answer, if ever asked.

Title: Re:HOCl structure
Post by: jdurg on December 29, 2005, 09:31:43 AM

I have never seen lemonoman's structure either as H-O-Cl would give the proper number of bond to each species and wouldn't leave you with too many electrons on Cl and too few on O.

Title: Re:HOCl structure
Post by: Donaldson Tan on January 03, 2006, 02:18:11 AM

Quote from: peacefulltortoise on December 28, 2005, 06:32:06 AM

so Cl is centre atom and it has 2 bond pairs, 3 lone pairs. Could anyone tell me why?

lemonman's structure is just a visual display of the peacefulltortoise's description.

The structure is wierd. After hydrogen has bonded with chlorine, why should chlorine even bond to oxygen?