CH3410, Test 1 (20 points), C00

1. (12 points) Using the first row as a model, complete the following table:

Formula

Lewis Structure

Total Number of

resonance forms

Oxidation state of central atom

molecular shape

stereochemical drawing

SO2

3

4+

bent

H3PO4

SO3

S in center, double bonded to 1 O, single bonded to 2 Os

7 (3 with one double bond, 3 with 2, one with 3)

6+

trigonal planar

N2O4

N single bonded to N, each N double bonded to one O, single bonded to the other

4

4+

trigonal planar at both Ns

HNO3

H single bonded to O single bonded to N; one O double bonded to N, third O single bonded to N

2

5+

trigonal planar at N; bent (109) at O

 

3. (8 points) Propose a formula for the oxoacid of Ge4+. Develop the predominance diagram for the oxoacid. Add sufficient hydroxide to give a neutral molecule. Thus Ge(OH)4. Use pKa = 8.5 - 5.7x + 10.2q = 8.5 - 0 + 0 = 8.5. Thus there should be a vertical line at pH 8.5 separating the predominance regions of Ge(OH)4 (left of line) and GeO(OH)3- (right of line). There should be another vertical line 4.5 pH units higher, at pH 13, separating GeO(OH)3- and GeO2(OH)22-.