Question

1. Why are double bonds and triple bonds shorter than single bonds? 

2. VSEPR geometry predicts that the bond angles in formaldehyde (CH20), a trigonal planar molecule, will be 120° throughout all three angles. However, analysis showed that the H-C-H bond angle is slightly smaller at 116.5°, while the two H-C-O angles are slightly larger at 121.8°. Explain this difference in the predicted bond angle vs actual bond angle. 

3. VSEPR geometry also predicts that the bond angles in tetrahedral molecules is 109.5'. However, in the case of ammonia (NH3), analysis showed that the H-N-H bond angles are 107.3°. Explain this difference in the bond angle. 

4. What is electronegativity, and why is it used to determine bond polarity? 

5. Which among the molecules above has a resonance structure? What did you found to be common among them that is required to have a resonance structure?

Answer 1

120 109 28' con =3 [a)- 2 sp. non polas 180 er u-2 [3+3) = 3 spr nonpolas . CHCl = 2(4+4) 2.4 sp polas cola Had[9+4)= 4 fp? non-polan 10g 2' Bot - 2 [6+3-1) = a spe poles " 109 28' 4 -2(6+2) = a so polar log 26 Pfs nad(ses) as sped nompelan ng + - 2 (3-1) - 2 & astigheter som ng - H=255H) - 3 spl 120 polan, xer, - 11882) 25 Spd nonpola, PO3 42215 + 8) = 4 s3 logize' polan sta bok(844) et sped polon By Hercer a p IngeBr B Polar BB2 cza Brnom polo to polas