Periodic trends & Bonding (Ch 12 &13)

1. Fill in the following table:

Property Trend NotesSize (radius)

Ionization energy

Electron affinity

Electronegativity

Bond polarity

Periodic trends & Bonding (Ch 12 &13)

2. Put the following in order of:

a. increasing atomic size Si Ca Ge

b. increasing ionic radius Cl- Ca2+ Ar

c. increasing ionization energy C N O

d. least to most exothermic electron affinity

C Si In

e. increasing electronegativity C F Cl

f. increasing polarity C-N C-O C-C

Periodic trends & Bonding (Ch 12 &13)

3. The successive ionization energies for an unknown element are shown below.

IE1 = 580 kJ/mol

IE2 = 1815 kJ/mol

IE3 = 2740 kJ/mol

IE4 = 11,600 kJ/molTo which family in the periodic table does the unknown element most likely belong?

Periodic trends & Bonding (Ch 12 &13)4. Draw Lewis Structures for the following. Show

resonance where applicable.

a. H2O

b. NCl3 c. HCN (carbon is central atom)

d. N2

e. CO2

f. NO3–

Periodic trends & Bonding (Ch 12 &13)

5. Draw two Lewis structures for the following molecules, one that obeys the octet rule and one that minimizes formal charge:

a. BeF2

b. POCl3

c. BF3

d. SO42-

Periodic trends & Bonding (Ch 12 &13)

6. Given the following bond lengths, estimate bond lengths for the following ions:

N-O 147 pm N=O 115 pm

a. NO-

b. NO+

c. NO2-

Periodic trends & Bonding (Ch 12 &13)7. Use the table of bond energies to estimate ∆H for the following reactions: Bond Bond Energy (kJ/mol) Bond Bond Energy (kJ/mol) H-H 432 C-H 413

H-Cl 427 O-H 467 C-Cl 339 N-H 391

O-O 146 N-N 160 O=O 495 N=N 418 C=O 745 N≡N 941 Cl-Cl 239 a. 2H2 + O2 → 2 H2Ob. 2NH3 → N2 + 3H2

c. CH4 + Cl2 → CH3Cl + HCl