Why does XeF4 have a square planar shape and why is the bond angle in SO2 120 degrees?
Ulex says After bonding with the fluorine, an Xe atom has 12 outer shell electrons. Four pairs of these are directed towards the fluorine atoms, each at the corner of a square. There is one lone pair above the plane of the square and one below. Hence the square planar shape. Think of it as being basically octahedral with the ‘top’ and ‘bottom’ apices occupied by lone pairs. After bonding with the oxygen, each sulphur atom in SO2 has 10 electrons. There are two double bonds, each with four electrons, joining the sulphur atom to the oxygens and one lone pairs. There are thus three regions repelling each other, giving a tetrahedral arrangement and thus a bond angle of 120 degrees – presumably double bonds and lone pairs repel each other to similar extents. Risk assessment Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures
