Exam 2 Review

Redox reactions

100

Identify the species being oxidized and reduced in the following reaction:

Fe + Zn²⁺ --> Fe²⁺ + Zn

Fe: oxidized

Zn: Reduced

200

Identify the species being oxidized and reduced in the following reaction:

Al + Fe²⁺ (s) --> Al³⁺ + Fe

Fe: reduced

Al: oxidized

300

Identify the species being oxidized and reduced in the following reaction:

4 K (s) + O₂ (g) → 2 K₂O (s)

O₂: reduced

K: oxidized

400

Identify the species being oxidized and reduced in the following reaction

Co (s) +  N₂ (g) --> 4 Co₃N₂

CO: oxidized

N₂: reduced

500

Identify the species being oxidized and reduced in the following reaction:

4 Fe (s) + 3 Cl₂ (g) → 2 Fe₂Cl₃ (s)

Fe: oxidized

Cl₂: reduced

Electron configuration/orbital diagram

100

Write the electron configuration in both full and abbreviated forms of K+.  How many valence electrons does K+ have?

1s2 2s2 2p6 3s2 3p6

[Ne] 3s2 3p6

8 ve-

200

Draw the orbital diagram for S^2-. How many valence electrons does S^2- have? 

8 ve-

300

Write the full and abbreviated electron configuration of Br-.  How many valence electrons does Br- have?

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6

[Ar] 4s2 3d10 4p6

8 ve-

400

Draw the orbital diagram for Ag+. How many valence electrons does Ag+ have?

1 ve-

500

Write the electron configuration in both full and abbreviated forms of Mg2+.  How many valence electrons does Mg2+ have?

1s2 2s2 2p6 

[He] 2s2 2p6

8 ve-

Geometry and Polarity

100

What is the molecular geometry of SiCl₄? What is the molecular polarity of this molecule?

tetrahedral, non-polar

200

What is the molecular geometry of SF₂? What is the molecular polarity of this molecule?

Bent, polar

300

What is the molecular geometry of BH₃? What is the molecular polarity of this molecule?

trigonal planar, non-polar

400

What is the molecular geometry of NH3? What is the molecular polarity of this molecule?

Trigonal pyramidal, polar

500

Which of the following molecules have dipole moments?

a. CS₂

b. CCl₂F₂

c. PCl₃ (P is the central atom)

d. ClNO (N is the central atom)

b. CCl₂F₂

c. PCl₃ (P is the central atom)

d. ClNO (N is the central atom)

Stoichiometry

100

How many grams of O₂ are produced by the decomposition of 68.0 g of H₂O₂?

2 H₂O₂ (aq) → 2 H₂O (l) + O₂ (g)

32.0 g O2

200

How many molecules of O₂ are needed to completely burn 8.2 kg of butane (C₄H₁₀). 

2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O

5.5 x 10²⁶ molecules  of O₂

300

How many particles of AlCl₃ will be produced if 12.0 mols of Al reacts with 10.0 mols of Cl₂?

2 Al (s) + 3 Cl₂ (g) → 2 AlCl₃ (s)

4.01 x 10²⁴ particles AlCl₃

400

What is the max amount of HBr that can be produced if 35.0 g of C₆H₆ reacts with 27.2 g of Br₂?

C₆H₆ + Br₂ → C₆H₅Br + HBr

13.8 g HBr

500

If 0.025 kg of potassium metal reacts with excess water, how many grams of potassium hydroxide are formed?

2 K + 2 H₂O → 2 KOH + H₂

72.3 g KOH

Intermolecular Forces

100

List the strongest intermolecular forces present in the following compounds.

1. SO₂

2. H₂O

1. dipole-dipole

2. Hydrogen bonds

200

List the strongest intermolecular forces present in the following compounds.

1. SCO 

2. PCl₃

3. SO₃

1. dipole-dipole

2. dipole-dipole

3. dispersion

300

What is the strongest type of intermolecular force present in CH₂Cl₂?

a. Dispersion

b. Dipole-dipole

c. Hydrogen bonding

d. Covalent bonding

e. Ionic bonding

b. dipole-dipole

400

Which of the following has the highest heat of vaporization?

a. CO2 

b. SO2 

c. H2O 

c. H₂O

500

Rank the following compounds from lowest to highest melting points? 

Br₂, Cl₂, I₂

Cl₂ < Br₂ < I₂