http://www.sgforums.com/forums/2297/topics/324229 en-US 60 <blockquote> <div class="quote_from">Originally posted by Bigcable22:</div> <div class="quote_body"> <p>do anyone know the bond angle for distorted tetrahedron?</p> <p>As above is bond angle for distorted tetrahedron applicable for a lvls?</p> </div> </blockquote> <p>&nbsp;</p> <p>The bond angles in the 'distorted tetrahedron' aka 'see-saw' molecular geometry, are approximately the same as in it's electron geometry, which is trigonal bipyramidal (ie. 5 electron pairs). An example of a molecular geometry with 5 bond pairs would be PCl5 (which is used often to indicate the presence of non-phenolic OH groups in Organic Chemistry).</p> <p>Thus, in a molecule with a distorted tetrahedron molecular geometry, eg. SCl4,&nbsp;note that the electron geometry is actually trigonal bipyramidal (ie. 5 electron pairs, it's just that the 5 electron pairs are made up of 4 bond pairs + 1 lone pairs, instead of all 5 being&nbsp;bond pairs like PCl5), of which the bond angles within are 90 deg and 120 deg.</p> <p>&nbsp;</p> <p>Thus, it follows that the bond angles in a distorted tetrahedron are also very close to 90 deg and 120 deg. You might expect the bond angles to be slightly less, due to greater repulsion by the lone pair. The extent of this repulsion and the actual bond angle depends on the specific molecule, the number of electron shells of the atoms within, etc.</p> <p>&nbsp;</p> <p>For 'A' level purposes, the candidates are expected to be able to see the (obvious) connection between electron geometry and molecular geometry, and hence&nbsp;deduce that the bond angles in a distorted tetrahedron molecule must be the same or at least very close to the bond angles in a trigonal bipyramidal molecule.</p> <p>&nbsp;</p> <p>But if your'e asking if in the 'A' level exam they will ask you to state the bond angles of a distorted tetrahedron, I don't believe they will (and I don't believe they ever had in the past papers). But if they do, simply state it as "approximately 90 deg and 120 deg", which you should already know are the bond angles of a trigonal bipyramidal geometry.</p> <p>&nbsp;</p> <p>&nbsp;</p> <p><img src="/images/emoticons/kde-3.5.8/redones/angel.png" alt= "angel.png" />&nbsp;Everyone Loves Chemistry! <img src= "/images/emoticons/kde-3.5.8/redones/angel.png" alt= "angel.png" /></p> Tue, 15 Jul 2008 12:23:01 +0800 www.sgforums.com:2297:324229:8243068 UltimaOnline http://www.sgforums.com/forums/2297/topics/324229 <p>male bonding?</p> Tue, 15 Jul 2008 03:17:12 +0800 www.sgforums.com:2297:324229:8242556 fatone http://www.sgforums.com/forums/2297/topics/324229 <p>As above is bond angle for distorted tetrahedron applicable for a lvls?</p> Tue, 15 Jul 2008 03:02:16 +0800 www.sgforums.com:2297:324229:8242552 Bigcable22 http://www.sgforums.com/forums/2297/topics/324229