chemistry final review

CHEMISTRY FINAL REVIEW

Types of Questions

• 45 multiple choice• 4 open ended

• 1 Molarity calculation• 1 Complete nuclear reaction and

name types of radiation• 1 Gas law calculation• 1 Stoichiometry calculation

Stoichiometry

• 11 multiple choice & 1 open-ended• 1-step• 3-step• Limiting reactant• Percent yield• Use your stoichiometry road map!

Iron (III) oxide is formed when iron combines with oxygen in the air.

How many grams of Fe2O3 are formed when 16.7 g Fe reacts completely with oxygen?

4 Fe + 3 O2 2 Fe2O3

A. 12.0 gB. 23.9 gC. 47.8 gD. 95.6 g

EXAMPLE

Percent Composition, Empirical & Molecular Formulas

• 6 multiple choice• Calculating % composition• Calculating Empirical/Molecular

Formulas• Identifying Empirical Formulas

Solutions

• 4 multiple choice & 1 open-ended• Calculating molarity• Calculating grams from molarity• Using molarity as a conversion factor• Calculating % yield

Gas Laws• 7 multiple choice & 1 open-ended• Combined Gas Law• Boyles Law• Ideal Gas Law• Charles Law• Use your Gas Laws formulas and

constants• STP• The properties of an ideal gas• Kinetic Theory

EXAMPLE

When the temperature of a flask containing 685 L of helium gas is held at 621 K, the pressure of the gas is 1890 kPa.

How many moles of helium does the flask contain?

A. 251 mol HeB. 25400 mol HeC. 207 mol HeD. 1.38 mol He

Graph Interpretation

• 3 questions• Directly proportional relationship• Indirectly proportional relationship

Nuclear Reactions & Atomic Structure• 14 multiple choice & open-ended • Atomic structure

• Isotopes, atomic number, mass number, properties of subatomic particles

• Complete nuclear reactions• Identify types of radiation• Half-life calculations• Calculate average atomic mass

Example Problems• The half-life of Zinc-71 is 2.4

minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed? a. 25.0 grams

b. 12.5 gramsc. 7.2 gramsd. 13.0 grams

Example Problem

• There is 1,728 grams of a radioactive material. After 24 hours there is 27 grams remaining. What is the half-life of the material? a. 24 hours b. 12 hoursc. 6 hours d. 4 hours

Example Problem

• What is average atomic mass of Lithium if 7.42% exists as 6Li (6.015 amu) and 92.58% exists as 7Li (7.016 amu)?

a. 7.42 amu b. 7.02 amuc. 6.52 amu d. 6.94 amu

Practice Problems

___ +

___ +

___ +

___ +

Bi21483

He42

Pu24694

Am24695

B95 Li53

Bi21483 e01

Example: Carbon-14 emits a beta particle as it undergoes radioactive decay to form nitrogen-14.