Carry out the memory work for Chapter 1. Also, study Section 1.9, focusing on the meaning and use of conversion factors.

Quiz

1. In the first question on the quiz, I will provide 2 of the symbols in Table 1.1. For each symbol, give the correctly spelled name of the corresponding element.
2. I will provide you the names of two elements. Give their symbols.
3. The third question on the quiz will be exactly like one part of Problem 1.37 or 1.43 at the end of the chapter. Work the problem using a conversion factor, as shown in Section 1.9.

Carry out the memory work for Chapter 2.

Quiz

1. I will provide names of two ions. Give their formulas, including their charges (the formula of an ion is not correct without its charge).
2. I will provide formulas of two ions. Give their correctly spelled names.
3. I will give the formula of a molecular compound (see Section 2.7). Give the correctly spelled name of the compound.

Quiz

1. I will give you the name of an element and ask you to compute the number of atoms in 0.100 g of that element. You need to know Avogadro's number (6.022 x 10²³) in order to answer. Remember to express your answer in the proper number of significant figures. See Example 3.4.
2. I will provide two formulas like those in Problems 3.23 and 3.24. One formula will be simple, containing no parentheses; the other will contain parentheses. Calculate the molecular mass of each substance. Round your answer to the nearest 0.1 amu. See Section 3.3.
3. I will provide an equation like one of those in Problem 3.59 or 3.60. Balance the equation with the lowest whole-number coefficients. For your answer on the quiz, I will ask you to write, in answer spaces 3a and 3b, the coefficients of the first (a) and second (b) components (reactants or products) in the balanced equation. See Section 3.7.

Reminder: Answers on quizzes must be completely correct in order to earn credit. Credit is based only on what you write in the answer space.

Carry out the memory work for Chapter 4.

Quiz

1. I will give you two formulas from Table 4.1, and ask you to classify each substance as S for strong electrolyte, W for weak electrolyte, or N for nonelectrolyte. Write the proper letter in the answer space.
2. I will give you one formula, and ask you to use the solubility rules of Table 4.2 (provided on the back of the quiz), to classify the compounds as S for soluble, I for insoluble, or ? if the rules do not allow you to decide. Write the proper letter in the answer space. See Example 4.1.
3. I will ask you to determine the oxidation number of two elements, applying rules 1-7 on pages 134 and 135 (rules not provided). The elements will be contained in the formula. Write the oxidation number (for example, +3, or 0, or -2) in the answer space. Be sure to include the sign, whether positive or negative. You are assign an oxidation number to a single atom of the element, even if more than one atom of that element is present. See Example 4.4.
   

Carry out the memory work for Chapter 5.

Quiz

1. I will give you a list of several gases from Table 5.1, and ask you pick one that is a monatomic gas, or one that is a molecular gas, at 25 C and 1.00 atm.
2. I will give you a list of units (mL, C, atm, mol), and ask you to pick one that is a unit of pressure, or of volume, or of temperature, or of quantity of substance. Be sure you can recognize various units for each property (examples [not complete lists]: atm and torr for pressure; mL and L for volume; F and K for temperature; mol and kg for quantity).
3. For the gas properties of pressure, temperature, and volume, I will ask you how a change in one property of a sample affects another property. Sample: "For an ideal gas sample with constant volume, decreasing the temperature will (increase, decrease, not change) the pressure." See Section 5.3.
4. I will ask you to solve the ideal gas equation (5.8) for one variable: pressure, volume, temperature, or number of moles. You will pick the correct answer from expressions provided.
5. I will give the number of moles of two gases in a mixture, and ask you to give the mole fraction of one of the gases. See Equation 5.13. (example: in a mixture of 4 moles of helium and 6 moles of hydrogen, the mole fraction of helium is 4/10.)

Carry out the memory work for Chapter 6, omitting any equations in section 6.3.

Quiz

1. I will give you two of the energy terms given in boldface on page 224. I will ask you to match them with the proper definitions given in italics on page 224.
2. I will describe a chemical or physical process involving heat change, and ask you whether the process is endothermic, exothermic, or neither. See Section 6.2 for examples.
3. I will give you a thermochemical equation, which is a chemical equation followed by enthalpy change, ΔH. I will ask you to give the enthalpy change for a related equation.
   Example:
   Thermochemical equation: A --> B ΔH = - 5 kJ/mol.
   For the reaction B --> A, ΔH = +5 kJ/mol (reversing reaction changes sign of ΔH).
   For the reaction 3A --> 3B ΔH = -15 kJ/mol (multiplying reaction by a constant multiplies ΔH by the same constant.
   See the section entitled Thermochemical Equations, beginning on page 235.

Carry out the memory work for Chapter 7. One new item was added recently.

Figure 7.23, page 292, gives the energies of the orbitals that are occupied by the electrons of atoms. The electrons of an atom live in, or "fill", orbitals according to these rules:
1. Electrons occupy the lowest-energy orbitals available.
2. Each orbital can hold only two electrons (Pauli exclusion principle).
3. Orbitals of equal energy share electrons as evenly as possible (Hund's rule).
4. The electron configuration of an atom gives the number of electrons in each occupied orbital.

During our coverage of this chapter, you will learn more about what the electronic configuration means and where it comes from, but it is useful just to be able to use simple rules to determine the correct configuration.

Examples: According to these rules, lithium, which has 3 electrons, has an electron configuration of 1s²2s¹. Helium (2 electrons) is 1s². Carbon (6 electrons) is 1s²2s²2p², or for short, [He]2s²2p². Learn to write the electron configurations of atoms, and to recognize elements by their electron configurations (with the help of the periodic table).

Quiz

1. I will name two elements and ask you to match each element with its electronic configuration from a list of several configurations.
2. I will give two electronic configurations and ask you to match each with one element in a list of several elements.
3. I will give you a wavelength of light and ask you to compute the energy of a photon of light having that wavelength, using equation 7.3 (which combines equations 7.1 and 7.2). OR, I will give you the energy of a photon and ask you to compute its wavelength. I will provide the constants h and c. See Example 7.3 and the accompanying Practice Exercise. Note that answers to Practice Exercises appear at the end of each chapter, after all problems.

Carry out the memory work for Chapter 8. Note that an item was added to memory work on 3/29/2007.

Quiz

1. I will give you two elements and ask you match each with its classification according to Figure 8.3. See Section 8.2.
2. I will give you two elements and ask you to match each with its outer-shell electronic configuration. See Section 8.2, Table 8.1, and Example 8.1.
3. I will give you one element and ask you to match it with the expected charge on a monatomic ion of that element. See "Electronic Configurations of Cations and Anions", pp. 321-2.

Carry out the memory work for Chapter 9.

Quiz

1. I will give you two elements and ask you to match each with its Lewis-dot diagram from a selection of diagrams like those in Figure 9.1. Your choices will all have the symbol E (for element) instead of the actual symbol for the element.
2. I will give you the correct Lewis diagram for a molecule, showing all bonds and unshared electron pairs. I will ask you to give the oxidation number of two specified atoms in the structure. See "Electronegativity and Oxidation Number", pp. 372 and 373. To answer this question, first assign the electrons in each bond surrounding the desired atom either to the atom or to its bonded neighbor, assigning them to the atom with higher electronegativity. (H < C < N < O < F). Also assign unshared electrons to the atom, if it carries any. Once you have assigned all electrons surrounding the atom, compute the oxidation number with this formula:
   
   (oxidation number of the specified atom) =
   (# valence electrons of the atom) minus (# electrons assigned to the atom)
   
   
3. For the same Lewis diagram as in question 2, I will ask you for the formal charge of one specified atom. See Section 9.7.

Carry out the memory work for Chapter 10.

Quiz

1. I will give you five three-dimensional drawings of molecules. The drawings will be "wedge/dot" diagrams like those on pages 1 and 2 of the laboratory Report Form for Experiment #10, and like the bottom row of diagrams in Figure 10.1, page 405 of Chang, 9th edition. I will ask you to match each model with the name of its molecular geometry, from a list of geometries taken from Tables 10.1 and 10.2 in Chang. Please note that I will be asking for molecular geometry, and not "arrangement of electron pairs".
   Careful study of Tables 10.1 and 10.2 should prepare you well for this quiz.

Carry out the memory work for Chapter 11. Read and study carefully Section 11.2 on intermolecular forces, the forces between molecules, which determine such properties as melting points, boiling points, and solubilities.

The intermolecular forces, from weakest to strongest, are as follows:
A. dispersion forces
B. dipole-induced dipole forces
C. dipole-dipole forces
D. ion-dipole forces
E. hydrogen bonding (a particularly strong type of dipole-dipole force), and
F. ionic forces (electrostatic attraction of ions of opposite charge).

When two molecules interact, they interact by the strongest forces available to them, because stronger interactions mean greatest stabilization of the interacting species. In Section 11.2 and its associated problems at the end of the chaper, you will find many specific examples of intermolecular interactions and the structural features necessary for each type (such as polar bonds, which are necessary for dipole-dipole interactions, and hydrogens on O, N, or F, which are necessary for hydrogen bonds).

Quiz: I will give you the above list of six intermolecular forces. In each of five questions, I will present one or more chemical or ionic species, and ask you for the strongest interation possible between them.

Examples
In the answer space, write the LETTER of the strongest intermolecular interaction of

1. H₂O molecules with each other. (answer: E)
2. CH₄ molecules with each other. (answer: A)
3. CH₄ molecules with CO₂ molecules. (answer: B)
   
   

Carry out the memory work for Chapter 12.
Study carefully Section 3, Concentration Units. Learn the definitions of the following concentration units: percent by weight, mole fraction (X) , molarity (M), and molality (m) . In addition, learn one more way of expressing concentration: percent (weight/volume) is the number of grams of solute per 100 mL of solution. Percent (weight/volume) is widely used in biology and medicine.

Quiz: I will give you a recipe for making an aqueous solution of solute E (molar mass provided) in water. I will ask you to calculate the concentration of this solution in all five of the units given above. Remember that the density or water is 1.00 g/mL, so 100 mL of water is 100 g of water. I will allow you 15 minutes for this quiz, and give you work space on the quiz page.

Here is a sample quiz, with correct answers. Your quiz will be identical except for the mass of solute E and the final volume of the solution (quantities in bold in the sample quiz below). You will be able to do this quiz only if you practice these exercises thoroughly beforehand.

Sample Quiz
Polly Ester adds 10.0 g of the solute E (molar mass 121.00) to 100.0 mL of water (molar mass 18.02), and mixes well until all of solute E has dissolved. The final volume of the solution is 102.7 mL. (Quantities in bold will be different on your quiz.)

1. Calculate the percent by weight of this solution.
   
2. Calculate the percent (weight/volume) of this solution.
3. Calculate the mole fraction of this solution.
4. Calculate the molarity of this solution.
5. Calculate the molality of this solution.

Answers;

1. 9.09%
2. 9.74%
3. 0.0147
4. 0.805 M
5. 0.826 m