polarity and lone pairs on lewis structures

[nyr201]

Hey all, on question #220 in destroyer Gchem, it says that SBr2 is polar bc of the lone pairs (2 lone pairs) giving a bent shape, i get that, however on question # 37 for XeF4 it also has 2 lone pairs but it has them on opposite sides and it explains that "opposing lone pairs cancel each other out, so its non polar"


my question is how do we know when lone pairs are opposing or next to eachother I guess u could say on XeF4 there isnt much room to put lone pairs near each other but even still on SBr2 wouldnt lone pairs wanna be farther from each other rather than close? is this a mistake in the book or am i missing something? i wish i could draw the structure but if u guys have destroyer 2010 ed u can look to see. thanks in advance

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[gigawatt]

Hey all, on question #220 in destroyer Gchem, it says that SBr2 is polar bc of the lone pairs (2 lone pairs) giving a bent shape, i get that, however on question # 37 for XeF4 it also has 2 lone pairs but it has them on opposite sides and it explains that "opposing lone pairs cancel each other out, so its non polar"


my question is how do we know when lone pairs are opposing or next to eachother I guess u could say on XeF4 there isnt much room to put lone pairs near each other but even still on SBr2 wouldnt lone pairs wanna be farther from each other rather than close? is this a mistake in the book or am i missing something? i wish i could draw the structure but if u guys have destroyer 2010 ed u can look to see. thanks in advance

Bottom line: lone pairs repel more than bonding domains, so the priority is keeping them as far apart as possible.

XeF4 has octahedral electron geometry with the two lone pairs opposing 180 degrees = nonpolar (XeF4 is square planar molecular geometry as a result).

SBr2 has tetrahedral electron geometry with two lone pairs. No matter how you place the two lone pairs, it is all the same, and the molecular geometry is bent (resulting in a molecular dipole).

 

[nyr201]

Bottom line: lone pairs repel more than bonding domains, so the priority is keeping them as far apart as possible.

XeF4 has octahedral electron geometry with the two lone pairs opposing 180 degrees = nonpolar (XeF4 is square planar molecular geometry as a result).

SBr2 has tetrahedral electron geometry with two lone pairs. No matter how you place the two lone pairs, it is all the same, and the molecular geometry is bent (resulting in a molecular dipole).

thanks idk how that slipped my mind lol damn vsper