Chemistry Level 1 and 2

Cheshire High School

Although topics such as:

-          Balancing chemical reaction

-          Significant figures for multiplication and division

-          Rules for rounding for addition and subtraction

-          Naming compounds

-          Writing formula equations from word equations

-          The mole and molar mass

-          Etc

Were not directly covered the second half of the year, those topics are intimately interwoven into the fabric of chemistry and serve as the backbone of the concepts covered following the midterm.  As such, knowledge of the above topics are quite important to review when studying for the final.

The exam will cover in depth chapters 4, 5 13, 14, 15, 16, 17, 18, and the first section from chapter 19 (pH and pOH).

For Level 1: 4, 5 13, 14, 15, 16, 17, 18, 19 and a taste of 20

The exam will also touch on a few topics from chapters 9 and 11.

General overview of the exam:

-          Multiple choice (between 60 – 70) designed to take an hour or less

-          Problems (15 – 20) designed to take approximately 45 minutes

-          Short answers (1 – 2) designed to take about 5 minutes each.

Total time for exam: 1 hour 55 minutes

-          This time does not include the time required to distribute the materials.

General advice for studying:

-          There is a large quantity of material to study for the exam- do not wait till the last minute to study

-          The most challenging part of the exam is recognizing which type of question you are dealing with.  My best suggestion for you is to randomly take questions from different practice problem worksheets and copy them to a separate sheet of paper (tonight or tomorrow night).  Put that sheet of paper aside and do not look upon it until you have studied for the exam.  At that point in time- since the problems are mixed- you should attempt to answer the questions.  If you do this right- you will be able to recognize problem type effectively.

Chapter 13: Gases

Vocabulary of Concern

-          Diffusion

-          Ideal Gas

-          Absolute Zero

-          Boyles Law                                

-          Charles Law

-          Elastic collision

-          Inelastic collision

-          Diffusion

-          Ideal Gas

-          Pressure

-          Inverse relationship

-          Direct relationship

-          Effusion

-          Density

-          Real Gas

-          Avogadros Law

Concepts of Concern

-          6 Properties of a gas

-          The kinetic molecular theory

-          What is the difference between an elastic and inelastic condition

-          6 parts of the Kinetic molecular theory

-          Variables that affect the volume of a gas (amount of gas (n), volume (v), temperature (t), and pressure (p)

-          What creates atmospheric pressure?

-          How does a barometer measure atmospheric pressure

-          How do barometers and manometers differ

-          How does increased water vapor affect atmospheric pressure and why

-          What is STP

-          The gas laws- the relationship between pressure and volume; the relationship between pressure and temperature; and the relationship between volume and temperature

-          Daltons law of partial pressures- how does the partial pressure of a gas change if the amount of gas is increased

-          When does the ideal gas law fail to accurately describe the behavior of a gas

-          How does a real gas differ from an ideal gas

-          Figure 13-23

-          Which gases are used for lifting gases, and why are some not used

-          How is effusion related to particle size and whole size

Problems of Concern

1.  A 4.1 mL sample of argon gas at 0.001°C has a pressure of 60.1 atm.  If the gas is heated to 88.01 C, what is the final pressure in kPa if the volume remains constant?

2. A mixture of carbon dioxide and hydrogen gas is collected that has a total pressure of 452.23 mm Hg.  If 23.4 mm Hg is from carbon dioxide gas, what is the partial pressure of hydrogen gas in the mixture in pascals?

3. A sample of unknown gas weighs 323.4 g and occupies 23.8 mL at 42.9 torr and 12.72 C.  What is the molar mass of the unknown gas?

4. Sketch a manometer that would show the following scenario: atmospheric pressure is 770 mm Hg.  The pressure in the closed manometer is 39.2% of the atmospheric pressure.  What is the difference in atm of the atmospheric pressure and the enclosed gas?

Chapter 14: Condensed States of Matter

Vocabulary of Concern

-          condensed states

-          intramolecular force

-          intermolecular force

-          induced dipole

-          dispersion force

-          dipole-dipole force

-          hydrogen bond

-          viscosity

-          surface tension

-          crystalline solid

-          amorphous solid

-          covalent network solid

-          vaporization

-          condensation

-          evaporation

-          equilibrium vapor pressure

-          boiling point

-          heat of vaporization

-          heat of fusion

-          sublimation

-          deposition

-          heating curve

-          phase diagram

Concepts of Concern

-          How and why does the K-M theory apply to liquids and solids

-          Figure 14-3

-          What is an intermolecular force- how does it differ for solids, liquids, and gases

-          What is a intramolecular force

-          What is a dispersion force and where does it align on the strength of bonds scale

-          Types and strengths of intermolecular bonding

-          What is viscosity and why does  a liquid possess it

-          How does the type of bond present affect certain variables like state, freezing point, and boiling point

-          What types of substances would have higher boiling points- types of intermolecular bonding

-          What are the unusual properties of water and what accounts for these properties

-          Types of solids- what are the types of solids and how do they differ from each other

-          How is bonding in solids different than bonding in liquids

-          What is the difference between molecular solids, metallic solids, ionic solids, and covalent network solids how do these differences influence properties like boiling and melting points.

-          Be able to identify the points on a heating curve- where does vaporization occur

-          Be able to identify the points on a phase diagram- understand in terms of bonding what is happening at each before and during each phase change

Problems of Concern

1. It takes 6 kJ to convert a mole of ice into water.  If 529 kJ of energy are absorbed, how much ice was turned to water?

2. It takes 41 kJ of energy to convert a mole of water into steam.  If 7000 grams of water need to be converted to steam, how much energy must be absorbed by the liquid water to convert all the liquid to steam?

Chapter 15

Vocabulary of Concern

-          Solution

-          Solute

-          Solvent

-          Soluble

-          Insoluble

-          Allow miscible

-          Immiscible

-          Aqueous solution

-          Concentration

-          Molarity

-          Molality

-          Mole fraction

-          Saturated

-          Unsaturated

-          Supersaturated

-          Solvation

-          Hydration

-          Solubility

-          Colligative property

-          Vapor pressure reduction

-          Boiling point elevation

-          Freezing point depression

-          Osmosis

-          Osmotic pressure

Concepts of Concern

-          What is a solution; a mixture

-          What are some properties of a solution

-          What is the solute, solvent, solution

-          What are the different types of solutions; how do they differ in terms of saturation and miscibility

-          Figures 15-3

-          Types of concentrations- molarity, molality, and mole fraction

-          How do solutions form- solvation and hydration

-          Figure 15-4

-          How does temperature affect solubility

-          How does pressure affect solubility

-          What factors affect the rate of dissolving

-          What defines a colligative property

-          What are the four basic colligative properties

-          What underlies the properties- why do they exist

-          How is molar mass related to freezing point reduction and boiling point elevation

Problems of Concern

1. What is the molality of a solution containing 230 g of bromine in 875 g of carbon tetrachloride (CCl₄)?

2. How much Iodine, in grams, should be added to water to produce 2.5 L of a solution with a molarity of .60M?

3. A solution contains the following gases with the mole fractions indicated: NH₃ (.214), Cl₂ (.453), and CO₂ (unknown).  What is the mole fraction of carbon dioxide in this solution? 

4. In the above solution, if the total number of moles was 24.34 moles, how many grams of carbon dioxide were present

5. If 3.2 g of fluorine gas were added to the mixture in six, what is the new mole fraction of each component in the mixture, given the information in both problem three and four

6. What is the freezing point depression when 125g of bromine is added to 755g of benzene (C₆H₆)? The freezing point depression constant is 5.12 C/m.

Chapter 16: Chemical Equilibrium

Vocabulary of Concern:

-          Reversible reaction

-          Chemical equilibrium

-          Law of mass action

-          Equilibrium constant

-          Equilibrium expression

-          Law of chemical equilibrium

-          Equilibrium position

-          Homogenerous equilibria

-          Heterogeneous equilibria

-          Reaction quotient

-          Le Chatelier’s principle

-          Haber process

Topics of Concern

-          What is a reversible reaction and why would a reaction reverse?

-          At what point does a chemical reaction reach equilibrium?

-          Does the reaction stop at the point of equilibrium?

-          Is the concentration of products and reactants equal at equilibrium?

-          Is the rate of reaction equal at equilibrium?

-          Why are solids and liquids not included in equilibrium constants?

-          What is an equilibrium expression?  What is the general form for an equilibrium expression?

-          What is the difference between equilibrium position and equilibrium constant?

-          What does an equilibrium constant measure?

-          What is the difference between hetero and homogeneous equilibrium

-          How does one determine whether a reaction has attained equilibrium?

-          What is Q?  How does it relate to equilibrium?

-          What is Le Chatelier’s Principle?  How does changing [ ], pressure, and temperature affect a reaction?

-          Is there a difference in equilibrium when the reaction is exothermic vs. endothermic and temperature is changed?

Problems of Concern:

1. Write the equilibrium expressions for the following reactions.

HCl (g) + O₂ (g) ⇌ H₂O (g) + Cl₂ (g)

2. What equation can be derived from the following equilibrium expression:

  [HI]²

[H₂][I₂]

3. For the reaction: N₂O₅ (g) ⇌ NO₂ (g) + NO₃ (g) the equilibrium concentrations of the reactant is .3 M and the concentration of both products are 4 M.  If .5M of N₂O₅ is added to the reaction and 1.4 M of NO₂ and 1.2 M of NO₃ is removed, what direction will the reaction proceed to reestablish equilibrium.

4. For the reaction: Al (s) + H₂SO₄ (g) ⇌ Al₂(SO₄)₃ (g) + H₂ (g) + Heat.  The equilibrium mass of aluminum is 54.2 g, sulfuric acid is 23.2 g, aluminum sulfate is 46.2 g, and hydrogen is 86.3 g.  What is the equilibrium constant for this reaction

If 14.2 grams of Hydrogen were removed and 20.2 grams of sulfuric acid were removed, which direction would the reaction proceed to reestablish equilibrium. Explain.

If. 15.4 grams of Hydrogen were added to the reaction and 14.2 grams of Aluminum were added, which direction would the reaction proceed to reestablish equilibrium.  Explain.

Chapter 17: Solubility and Precipitation

Vocabulary of Concern

-          Dissociation

-          Precipitation

-          Dissolution

-          Ionization

-          Solubility product

-          Solubility equilibrium

-          Ion product

-          Precipitation reaction

-          Complete ionic equation

-          Spectator ion

-          Net ionic equation

-          Common- ion effect

Topics of Concern

-          What is the difference between solubility equilibrium and chemical equilibrium?

-          How are dissolution and precipitation related?

-          What happens when an ionic solid is dropped in water (how does water align itself to the ionic crystal).

-          What types of substances are contained in the solubility product expressions

-          Be able to go from solubility product to concentration and from concentration to solubility product (the use of variables to solve for concentrations).

-          What does it mean to be sparingly soluble

-          When a solution is diluted- how do you figure out whether or not a sparingly soluble precipitation reaction occurs?

-          What is a precipitation reaction and why does it occur

-          How does the ion product help predict whether a precipitation reaction will occur?

-          What two factors are needed for a precipitation reaction to occur.

-          How are net ionic and complete ionic reactions related?

-          What is the net ionic equation useful for?

-          Why is the net ionic used for solubility products equilibrium?

-          How does a common ion effect the equlibrium position

**** the equilibrium constant is not affected by a common ion- the position is- the constant is a constant and does not change *****

Problems of Concern:

1. Give the three step ionic equations for the following reactions:

1. The reaction between (NH₄ )₂CO₃ (aq) and Ag₂SO₄ (aq)

2. A 45 mL sample of 1 x 10^-2 M NaCl is added to 15 mL of 2.3 x 10^-4 M AgNO₃.  Does a precipitate form if the solubility constant for the solid is 1.6 x 10^-10

1. If the mixture were allowed to stand for several days in hot room and 25 mL of the water evaporated from the solution, would this change whether or not a precipitate formed?

3. What are the equilibrium masses of both the Calcium ion (Ca²⁺) and the Phosphate ion (PO₄^3-) in a saturated solution of calcium phosphate if the solubility product constant for the dissolution is 2 x 10^-29? (assume 1L of total solution)

Chapter 18/19 Acids and Bases

Vocabulary of Concern

-          Acid

-          Base

-          Indicator

-          Neutralization

-          Salt

-          Hydronium ion

-          Amphoteric

-          Conjugate acid

-          Conjugate base

-          Acid dissociation constant

-          Base dissociation constant

-          Salt hydrolysis reaction

-          Acidic hydrogen

-          Self ionization

-          Ion product constant

-          pH

Concepts of Concern

-          What are the differences between the definitions of acids and bases that have been proposed

-          What are the general properties of an acid and how do those properties differ from a base? (reaction with metals, tastes, electrical conductivity, indicators)

-          How is the hydronium ion formed?

-          What type of substances can be amphoteric

-          Be able to identify acid base conjugate pairs

-          What is the relationship between strength of an acid and its conjugate base?

-          What is meant by the strength of an acid

-          Can a weak acid ever have the same pH as a strong acid when ionized in water? And why?

-          What does the acid dissociation constant tell you about an acid

-          Know how to go from concentration to K_a and from K_a to concentrations

-          Know the relationship between the mixture of strong acids with weak bases, etc (pg 614)

-          Know how to name acids

-          Be able to describe the auto ionization of water

-          Be able to go from pH to concentration and from concentration to pH

-          Be able to go from pH to pOH and know the relationship

-          Know how dissolving an acid in water will shift the ions.

Problems of Concern

1. What is the pH of a solution produced by dissolving .1 mole of sodium hydroxide (NaOH), a strong base, in 26.1 L of water? 
2.  
3. What is the pH, the pOH, the OH^- concentration of a solution with a hydronium ion concentration of 8.6 x 10^-8M.  Is this solution acidic, basic, or neutral.

4. If the pOH of a solution is 3.2, what is the concentration of hydronium ions in solution?

5. A weak monoprotic acid, acetic acid, has an equilibrium concentration of hydronium ions of 3.3x 10^-3 M.  If 4.3 x 10^-5 grams of acetic acid was dissolved in .0023 mL of water, what is the acid dissociation constant for this acid?

1. What is the hydroxide ion concentration in this solution

6. A weak base, methylamine, (CH₃NH₂), has an equilibrium concentration of hydroxide ions of 9.8 x 10^-12 M.  If the initial concentration of methylamine was .93 M, what is the base dissociation constant for this base?

Name the acids:

7.  HNO₂                ____________________                ____________________

8.  H₃PO₃                ____________________                ____________________

For the following equation label the acid (A), the base (B), the conjugate acid (CA), and the conjugate base (CB) on the lines provided below the chemical formula.

NH₃ (aq) +                 H₂O (l) ⇌            NH₄⁺ (aq) +      OH^-

_______                _______                _______                _______

Chapters 4, 5, 19, and 20 on their way!