Exam 3

1

100

Which of the following Group 5A elements is the most electronegative?

a. P

b. As

c. Bi

d. N

e. Sb

d. N

200

Using the periodic table, determine the Lewis dot structure for phosphorus. How many paired and unpaired electrons are there?

a. 6 paired, 1 unpaired

b. 1 paired, 4 unpaired

c. 5 paired, 0 unpaired

d. 2 paired, 3 unpaired

e. 3 paired, 2 unpaired

d. 2 paired, 3 unpaired

300

How many sigma and pi bonds are in the molecule CH₂O?

a. 4 sigma, 0 pi

b. 3 sigma, 1 pi

c. 2 sigma, 2 pi

d. 1 sigma, 3 pi

e. 0 sigma, 4 pi

b. 3 sigma, 1 pi

400

What is the correct Lewis structure for sulfur dioxide?

a. (refer to structure on board)

b.(refer to structure on board)

c.(refer to structure on board)

d.(refer to structure on board)

e.(refer to structure on board)

d.(refer to structure on board)

500

How many resonance structures does PO₄^3- (phosphate anion) have?

a. 0 (it has no resonance)

b. 1

c. 2

d. 3

e. 4

e. 4

2

100

Of the bonds present in the molecule below, the triple C-N bond is predicted to have the ___ energy and the ___ length.

a. highest, longest

b. highest, shortest

c. lowest, longest

d. lowest, shortest

e. cannot compare w/ given info

b. highest, shortest

200

Which of the following bonds is the most polar?

a. N-Br

b. C-Br

c. B-Br

d. O-Br

e. F-Br

e. F-Br

300

What is the electron domain and molecular geometry for PO₄^3-?

a. tetrahedral, tetrahedral

b. tetrahedral, trigonal pyramidal

c. trigonal bipyramidal, T-shaped

d. octahedral, square planar

e. trigonal bipyramidal, seesaw

a. tetrahedral, tetrahedral

400

How many bonding and nonbonding domains are there for the center atom in CO₃^2-?

a. 4 bonding, 0 nonbonding

b. 3 bonding, 0 nonbonding

c. 3 bonding, 1 nonbonding

d. 2 bonding, 2 nonbonding

e. 2 bonding, 1 nonbonding

b. 3 bonding, 0 nonbonding

500

Of the molecules listed below, which is non polar?

a. NH₃

b. HF

c. SO₂

d. F₂

e. CHF₃

d. F₂

3

100

What is the formal charge on the sulfur atom in the sulfate ion?

a. -2

b. -1

c. 0

d. +1

e. +2

c. 0

200

For the bromine ion, how many valence electrons are present and what is the overall charge?

a. 6 e-, +1

b. 7 e-, 0

c. 8 e-, -1

d. 4 e-, 0

e. 7 e-, -1

c. 8 e-, -1

300

Which set of orbitals forms the sigma bond between hydrogen and carbon in HCN?

a. s and s

b. s and sp

c. sp and sp

d. s and sp²

e. sp and sp²

b. s and sp

400

Which of the following anions has a center atom that has more than an octet?

a. BO₃^3-

b. SO₄^2-

c. NO₂^-

d. CO₃^2-

e. BrO^-

b. SO₄^2-

4

100

Which of the following answers has Period 3 oxide salts written in order of increasing lattice energy?

a. MgO < Na₂O < Al₂O₃

b. MgO < Al₂O₃ < Na₂O

c. Al₂O₃ < MgO < Na₂O

d. Na₂O < MgO < Al₂O₃

e. Al₂O₃ < Na₂O < MgO

d. Na₂O < MgO < Al₂O₃

200

Going from left to right, determine the hybridization for each non-H atom in the following molecule

a. sp², sp²

b. sp, sp²

c. sp³, sp²

d. sp³, sp³

e. sp², sp

a. sp², sp²

300

in an sp²-hybridized atom where there are 3 electron domains, __ s and __ p orbitals are combined to form __ sp² orbital(s).

a. 2,2,3

b. 1,3,1

c. 1,3,4

d. 1,3,3

e. 1,2,3

e. 1,2,3

400

Which of the following molecules has an sp²-hybridized carbon?

I. HCN

II. CCl₄

III. CH₃Cl

IV. CH₂O

a. I

b. I and IV

c. II and III

d. II and IV

e. IV only

e. IV only