Question

Answer the following on a separate sheet of paper. 1. Using the data collected for PF, SF, and CIF, what structural comments can be made about molecules with more than four groups (charge clouds) around the central atom? 2. Select which structure is preferred and discuss why? SC 3. To assess the stability of the axial versus equatorial positions for a trigonal bipyramidal structure, a computer program was used to determine the energy to assess SF, with the lone pair in either position (axial or equatorial). The data obtained is shown below: Equatorial: Energy = -795.14 au Axial: Energy = -795.088 au A. Using the conversion factor 627.5096 kcal = 1 au, what is the energy difference in kcals between the two structures? B. According to these data, which structure is more stable (more negative)? C. Does this agree with your explanation from the previous question? Why or why not? 4. Below is a table that lists dipole moments and bond angles calculated by a computer program for three molecules. Discuss why the bond angles differ and describe the significance for the dipole moment difference. Note: a Debye measures electric dipole moments. Molecule Methane Ammonia Water Dipole moment 0.00 Debye 1.84 Debye 2.15 Debye Bond Angle 109.47 107.57° 105.93 5. Below is a table that lists dipole moments for three molecules. Discuss the ionic and covalent character of each compound using the dipole moment values. Molecule H2 HF LiH Dipole moment 0.00 Debye 1.94 Debye 5.95 Debye

Answer 1

sfy UF PES Eas) 35² 373 S93) 350 309 See) 362 363 31' Sp 3d hybr cligs) 3,2 3p5 Chies) 35² 3p4 3d sp 3d hyba 35' 3p 3d spsd hyb with a lone pair with 2 love Hüf ローター VB sketch see-saw shape. moteuutar Trigonal Bipyramidal Geometry Trigonal Dipyramid T-shaped Trigonal Brown Trigonal Beppramed. Irigonal Bipyramid electron Trigonal Bipyramid geometry J7 +21= 280 6+28. = 34€ toe 5 + 35240 Valence Electron Lewis str. VSEPR sketch F-P. U-F 1 -

In case of Sfy is is I F the structure as lone pain tend to stay on the equito rial position due to more of. S- Character. E. E= ep on lp, on ut ~ 795 - 14 au =9.989x105 kaal - 795.08 au 4000 equitorial axial it sfy with Sty with - Kcal. stable as its clearly energy sfy with ep on equitorial is more as len Methane # Sp3 Lчь 109.41 u20 Tetrahedral Shape H T as their is no EN diff blue c and t u=0 Ammonia XNXX u= 1.84 Debye H sp3 hyb" with 1 lp Bond angle decreases from 109.5 to 107.5° Os pole Merment water 2 Up present : High U=2.15 spe hybn with 2 lp . Bond angle decreases to los.go

Page H2 H - H pure covalent bond no Electro negitivity har difference l=0 HE Floutrine being the shared This bond thus - M = 1.94 most electronegitive element a pair of electron towards itself have some it Conic character Debye. of win 7 lue bat in - Lit H This is an ionic bond and high dipole moment = 5.95 this Debye... very