Question

What are the regions of electron density for
CO2
OF2
SO3
PCI3
IF6

Answer 1

do they want you to draw it?

Answer 2

No I'm just suppose to write the answer

Answer 3

how are you supposed to do that?

regions of high electron density are intramolecular regions (between atoms) and where the lone pairs are located

Answer 4

check this: http://www.chem.purdue.edu/gchelp/vsepr/rule2ex.html ,

also, Main Group molecule: AXnEm A:X a pair of electrons involved in normal covalent bond (also A=X, C=O, S=O) A:E a lone pair of electrons on the central atom.
The geometry (and "hybridization") adopted by A depends on both types of pairs of electrons (n + m) but when naming the structure the lone pairs are ignored (they cannot be detected by physical techniques). The structure is the one that minimizes the repulsion between the electron bond and lone pairs.
1) CO2 is AX2 linear (sp hybridization) no lp
2) OF2 is AX2E2 (like H2O) based on tetrahedral sp^3 hybridization but two sites occupied by lone pairs hence bent or V-shaped.
3) SO3 AX3 trigonal planar (sp2 hybridization) no lp
4) PCl3 AX3E: Based on tetrahedron (sp^3) but one site occupied by lone pair: trigonal pyramidal (like NH3)
5) IF6 AX6E(0.5) Does not exist. Could be IF7 (pentagonal bipyramid); [IF6]^+ (most likely) AX6 octahedral;
[IF6]^- (?) distorted octahedral