AP Chemistry MidTermExam ReviewNova High School

Exam Format

Section I: Multiple Choice -50%

-25 questions (2 point for each correct answer)

-30 minutes to complete, NO calculators permitted

-No point deduction for questions left blank and NO point deduction for incorrect answers.

Section II : Free-Response-50%

Long Response- 2calculation problems (30 pts total)

- 35 minutes to complete, calculators permitted

- Possible Topics

  • Stoichiometry basic application
  • Solution/stoichiometry
  • Gas/stoichiometry problem
  • Lab application

Short Response- 1 short response (20 pts total)

- 10 minutes to complete, calculators permitted

- Possible Topics

  • Lewis structures & VSEPR Theory
  • Periodic trends & Quantum Mechanical Model
  • Gases & Intermolecular Forces

Total Exam - - 100%

Section I – Multiple Choice Content

No calculator or use of equation sheets is permitted.

General Info/Descriptive/Lab______

  • Classifying Matter
  • Be able to classify as elements, compounds, mixtures
  • Descriptive
  • Be able to identify descriptive colors from flame tests and ions in solution for common substances
  • Be able to identify characteristics of groups on the periodic table (including chalcogens, halogens, and noble gases)
  • Be able to identify metallic & non-metallic properties
  • Proper Lab Technique
  • Be able to describe filtration (and other types of gravimetric analysis), chromatography, titration (along with indicators), distillation, decantation, and gas collection techniques.
  • Lab Equipment
  • Be able to identify various lab equipment such as (but not limited to): Erlenmeyer & volumetric flasks, volumetric pipettes, and burets,
  • Physical vs. Chemical Properties
  • Be able to identify physical and chemical changes and separation techniques for both.
  • Physical: Filtration, distillation, chromatography
  • Chemical: Combustion, electrolysis
  • Reaction Classification
  • Know the 5 basic reaction types and identify if they are red-ox or not.

Atoms, Molecules, & Ions______

  • Atomic Structure & Sub-atomic particles
  • Be able to count protons, neutrons, and electrons from chemical symbols
  • Ions & Charge
  • Know how to predict oxidation states for main group elements from the periodic table.

Mass Relations in Chemistry: Stoichiometry______

  • Mole Concept & Avogadro’s Number
  • Be able to use the mole and molar mass in conversions
  • Empirical & Molecular Formula
  • Be able to use data from combustion analysis
  • Percentage Composition
  • Reaction Stoichiometry
  • Be able to identify limiting reactant
  • Be able to write a balanced chemical equation

Reactions in Aqueous Solution______

  • Red-ox Reactions
  • Be able to assign oxidation numbers
  • Be able to identify oxidizing and reducing agents
  • Double Replacement Reactions
  • Know solubility rules
  • Know how to write net ionic equations
  • Acid-Base
  • Know strong acids & bases
  • Know how to write net ionic equations
  • Be able to identify electrolytes

Gases, Solids, Liquids______

  • Ideal Gas Law
  • Be able to use in initial & final state problems
  • Be able to use in gaseous stoichiometry
  • Daltons Law of Partial Pressures
  • Be able to use to find total pressure of partial pressures
  • Mole Fraction
  • Know how to find mole fraction
  • Know how to find partial pressures using mole fraction

Electronic Structure & The Periodic Table______

  • Quantum Numbers
  • Be able to assign
  • Be able to identify invalid sets
  • Periodic Trends
  • Be able to define the three main trends
  • Be able to describe each of the three trends

Covalent Bonding & Lewis Structures______

  • Lewis Structures
  • Be able to draw for various molecules
  • VSEPR Theory & Molecular Geometry
  • Be able to predict geometry from Lewis Structure
  • Dipole Moments & Polarity
  • Be able to define and identify on a molecule

Section II - FRQ Practice

Calculator and use of equation sheets permitted.

Long Response– these 3 problem should take no more 60 minutes

1. Water is added to 4.267 grams of UF6. The only products are 3.730 grams of a solid containing only uranium, oxygen and fluorine and 0.970 gram of a gas. The gas is 95.0% fluorine, and the remainder is hydrogen.

(a)From these data, determine the empirical formula of the gas.

(b)What fraction of the fluorine of the original compound is in the solid and what fraction in the gas after the reaction?

(c)What is the formula of the solid product?

(d)Write a balanced equation for the reaction between UF6 and H2O. Assume that the empirical formula of the gas is the true formula.

2. A sample of dolomitic limestone containing only CaCO3 and MgCO3 was analyzed.

(a)When a 0.2800 gram sample of this limestone was decomposed by heating, 75.0 milliliters of CO2 at 750 mm Hg and 20oC were evolved. How many grams of CO2 were produced.

(b)Write equations for the decomposition of both carbonates described above.

(c)It was also determined that the initial sample contained 0.0448 gram of calcium. What percent of the limestone by mass was CaCO3?

(d)How many grams of the magnesium-containing product were present in the sample in (a) after it had been heated?

3. Answer the following questions about acetylsalicylic acid, the active ingredient in aspirin.

(a)The amount of acetylsalicylic acid in a single aspirin tablet is 325 mg, yet the tablet has a mass of 2.00 g. Calculate the mass percent of acetylsalicylic acid in the tablet.

(b)The elements contained in acetylsalicylic acid are hydrogen, carbon, and oxygen. The combustion of 3.000 g of the pure compound yields 1.200 g of water and 3.72 L of dry carbon dioxide, measured at 750. mm Hg and 25C. Calculate the mass, in g, of each element in the 3.000 g sample.

(c)A student dissolved 1.625 g of pure acetylsalicylic acid in distilled water and titrated the resulting solution to the equivalence point using 88.43 mL of 0.102 M NaOH(aq). Assuming that acetylsalicylic acid has only one ionizable hydrogen, calculate the molar mass of the acid.

Short Response – these 3 problems should take no more than 30-40 minutes

4. Write a balacned net ionic equation for the following reactions.

(a) A solution of ammonia is added to a dilute solution of acetic acid.

(b) Carbon disulfide vapor is burned in excess oxygen.

(c) Hydrogen sulfide gas is bubbled through excess potassium hydroxide solution.

(d) Sulfur dioxide gas is bubbled into an excess of a saturated solution of calcium hydroxide.

(e) A piece of lithium metal is dropped into a container of nitrogen gas.

(f) A solution of hydrogen peroxide is decomposed catalytically.

5. Use principles of atomic structure and/or chemical bonding to answer each of the following using the table below.

Ionization Energy (kJ/mol)
First / Second
K / 419 / 3,050
Ca / 590 / 1,140

(a)The radius of the Ca atom is 0.197 nanometer; the radius of the Ca2+ ion is 0.099 nanometer. Account for this difference.

(b)The lattice energy of CaO(s) is -3,460 kilojoules per mole; the lattice energy for K2O(s) is -2,240 kilojoules per mole. Account for this difference.

(c)Explain the difference between Ca and K in regard to

(i)their first ionization energies,

(ii)their second ionization energies.

(d)The first ionization energy of Mg is 738 kilojoules per mole and that of Al is 578 kilojoules per mole. Account for this difference.

6. Using principles of chemical bonding and/or intermolecular forces, explain each of the following.

(a)Xenon has a higher boiling point than neon has.

(b)Solid copper is an excellent conductor of electricity, but solid copper chloride is not.

(c)SiO2 melts at a very high temperature, while CO2 is a gas at room temperature, even though Si and C are in the same chemical family.

(d)Molecules of NF3 are polar, but those of BF3 are not.