Other topics in Chapter Bond strength and length, Polarizing Power and Polar Bonds

1. Other topics in Chapter Bond strength and length, Polarizing Power and Polar Bonds

2. Electronegativity

3. Notes for you: • Bond Strength is Measured in (D) • The stronger the bond the shorter the bond • E.G. A C-C single bond is always weaker and longer than a C-C triple bond. • Resonance structure bonds are intermediates between the structures. • Bonds are weaker and longer between larger atoms

4. Bond Strengths and Lengths Place the following molecules or ions in order of increasing bond length for the N-O bond. How does the strength of the bonds compare? NO, NO2 , NO3-, Hints: Draw all lewis structures Decide bond order How does that relate to bond strength?

5. Notes for you to use on following Problem • Polarizability • Electrons are farther from the nucleus • Nucleus has less pull on far off electrons • Larger electron cloud • More negative charge equals more polarizability • i.e. Br- is more polarizable than Cl-. • Small highly charged cations can polarize atoms easier. • Higher charge= tighter control over electrons • Small= tighter control over electrons. • I.E.: Al3+ can polarize another atom better than Na+ • Covalent Character vs. Ionic Character • Higher polarizing power with higher polarizability yields greater covalent character • I.E. MgI2 has more covalent character than NaCl

6. Polarizability and polarizing power Arrange the anions N3-, P3-, I- and At- in order of increasing polarizability. Decide which of each pair is more soluble in water? Hint #1: Which is more soluble in water Ionic or Molecular compounds? Hint #2: Which of the pairs have more ionic characters?

7. Electronegativity and Polar bonds • For each of the Lewis stuctures we did previously, decide which bonds are polar. (We will be using our previous slides and lewis structures)

8. Lewis Structures: non-octet breaking For each of the Lewis stuctures we did previously, decide which bonds are polar. • CH2O 4e-+1e*2+6=12e- O C H H

9. Lewis Structures: non-octet breaking For each of the Lewis stuctures we did previously, decide which bonds are polar. • BH3NH3 • 3e+5e+1e*6=14e H H N B H H H H

10. Lewis Structures: non-octet breaking For each of the Lewis stuctures we did previously, decide which bonds are polar. • N2O • 5e+5e+5e=16e N N O

11. Lewis Structures: For each of the Lewis stuctures we did previously, decide which bonds are polar. • BH3 H B H H

12. Lewis Structures: For each of the Lewis stuctures we did previously, decide which bonds are polar. • XeF4 F F Xe F F

13. Lewis Structures: For each of the Lewis stuctures we did previously, decide which bonds are polar. • ClF4- F F Cl F F

14. Lewis Structures: For each of the Lewis stuctures we did previously, decide which bonds are polar. +0 O • H2SO4 S +0 +0 O O O H H

15. Lewis Structures: [HCO2]- For each of the Lewis stuctures we did previously, decide which bonds are polar. +0 -1 O O C +0 C +0 -1 H H O O +0 +0 +0

16. Lewis Structures: O3 For each of the Lewis stuctures we did previously, decide which bonds are polar. +1 +1 O O O O O O +0 +0 -1 -1

17. Lewis Structures: [SO3]2- For each of the Lewis stuctures we did previously, decide which bonds are polar. -1 +0 -1 O O O +0 +0 +0 S S S -1 -1 +0 -1 -1 O O O O O O +0

18. Line Structures: CH3CHCHCOOH For each of the line structures we did previously, decide which bonds are polar. C-C bonds: C-H bonds: C-O bonds: O-H bonds: O OH H3C---CH---CH----COOH

19. Line Structures: NH2CH2CH(OH)CH3 For each of the line structures we did previously, decide which bonds are polar. C-C bonds: C-H bonds: C-O bonds: O-H bonds: N-H bonds: H2N OH H2N---CH2---CH(OH)----CH3