Chapter 2

In the Born-Haber cycle, the negative contributions to the enthalpy of formation come from  a. bond energy and lattice energy  b. electron affinity and ionization energy  c. electron affinity and lattice energy  d. heat of sublimation and ionization energy

Why does the octet rule not apply to transition metals?  a. the octet rule does apply to transition metals as they are all classified as metals b. transition metals do not form cations or anions c. most transition elements form ions with more than one positive charge d. transition elements cannot be assigned with charges to form ions What do you call the process of positive and negative ions of an ionic compound separating from each other when solubilized in water? a. dissociation b. solubilization c. differentiation d. precipitation Which of the following statements is considered true? a. The size of an atom is determined by the size of the outermost occupied orbital b. Higher ionization energy means that the electron is more difficult to remove c. both are correct d. both are incorrect

Why are transition metals special cases? a. They have two valence shells with complete octets that want to react. b. They have up to 8 electrons in their valence shell. c. They don’t react with other elements because they are actually noble gases. d. They have two valence shells with an incomplete octet that want to react. 9. Name the following compound, BrF5 a. Bromine pentafluoride b. Bromine fluoride c. Bromine (IV) fluoride d. Monobromine pentafluoride 10. Avron was conducting his science fair project when he came across a bottle of acid whose label read, “HSCN.” What is the name of the acid that is contained within the bottle? a. Hydrocyanic acid b. Hydrothiocyanic acid c. Thiocyanic acid d. This acid does not exist 11. What is the chemical formula for copper (II) hydroxide? a. Cu2(OH) b. CuOH c. CuOH2 d. Cu(OH)2

9. Which pair of atoms would form an ionic bond? a. bromine and oxygen b. chlorine and lithium c. carbon and nitrogen d. sodium and neon e. copper and chromium 15. Using only the periodic table, place the following atoms in order of increasing atomic radius: C, Ba, 0, Ca, and Ge. 21. What types of elements are bonded together to make an ionic compound? Give three examples of ionic compounds. Identify the types of elements that make up the compound in each example. 27. Describe how the physical state of a substance at room temperature depends on the strength of the intermolecular forces between the particles of the substance.

These form ionic compounds with large lattice energies. A. Small ions with small charges B.  Small ions with large charges C. Large ions with large charges D. Large ions with small charges

2a. Determine the theoretical lattice energy using the Kapustinskii's equation. 1.202 x 105 VZ*Z¯ U = 34.5 r* + r r* + r Ca2+ = 114 pm I = 206 pm b. Compare your answer to the experimental lattice energy of -1971 kJ/mol.

Is the distribution of electrons in the sodium-chlorine bond and carbon chlorine bond the same? For each case describe how the electrons that make up the bond are distributed between the two atoms.

What is the chemical element involved in Calcium Hydroxide? What are the chemical bonding and properties of Calcium Hydroxide?

Lattice energy is ________.     the energy required to convert a mole of ionic solid into its constituent ions in the gas phase     the energy given off when gaseous ions combine to form one mole of an ionic solid     the energy required to produce one mole of an ionic compound from its constituent elements in their standard states     the sum of ionization energies of the components in an ionic solid     the sum of electron affinities of the components in an ionic solid

10. You're preparing for a camping trip. you see two different stoves you can pack for your trip to do all your cooking. Which fuel would you prefer to carry? One stove uses fuel propane. The other stove uses naphtha (hexane) fuel. Start by writing a balanced combustion equation for both of these reactions. Use either standard enthalpies of formation or bond energies to determine the enthalpy changes for the combustion of these two fuels. Then suggest which stove, the one that uses propane or the one that uses naphtha, would you recommend to pack for your camping trip? Explain. (You may need more space for your response).

Which statement is NOT correct regarding the lattice energy of an ionic solid? a.Lattice energy of MgO is higher than NaCl, due to MgO's higher ionic charge and smaller ionic sizes b.As the lattice energy increases melting point increases c.It is the energy change when one mole of an ionic compound is created under standard conditions from its pure elements d.It is the energy change on formation of one mole of an ionic compound from its constituent ions in the gaseous state e.As the lattice energy increases solubility decreases

Suppose a chemist discovers a new metallic element and names it "Xtrinsium" (Xt). Xt exhibits chemical behaviour similar to an alkaline earth. Xt(s) + F2(g) → XtF2(s)   Lattice energy for XtF2 -2360. kJ/mol First Ionization energy of Xt  520. kJ/mol Second Ionization energy of Xt  936 kJ/mol Electron affinity of F -327.8 kJ/mol Bond energy of F2  154 kJ/mol Enthalpy of sublimation (atomization) of Xt      180. kJ/mol Use the above data to calculate ΔH°f for Xtrinsium fluoride.

3. In this experiment, you will be studying the oxidation strength of the halogens. a. What is the color of each of the halogens that you will be working with in this experiment?    b. Write Lewis dot structures for each of the halogen molecules: F2, Cl2, Br2, and I2.      c. On the basis of periodic trends, which of the halogen molecules do you expect to have the shortest bond? Explain why.

The potential energy curves for two substances are shown. One curve represents two atoms interacting through a London Dispersion Force and the other curve represents two atoms forming a covalent bond. Which curve represents the atoms that form a covalent bond? a.The solid line because the atoms are further apart when the covalent bond forms. b.The solid line because it takes more energy to separate the atoms. c.The dotted line because the atoms are closer together when the covalent bond forms. d.The dotted line because it takes less energy to separate the atoms. PE

2. Sulphur reacts with oxygen to form sulphur trioxide through sulphur monoxide and sulphur dioxide. Sulphur trioxide reacts with water to form sulphuric acid. Balance the equations for the above and draw the Lewis structures for each of the oxides and the acid. next page

44. Explain why the diatomic nitrogen atom is unusable by most plants. Where do plants get nitrogen?

7 Which of the following elements will have the fastest chemical reaction? A. Na B. Al C. Si D. P 8 Which of the following elements will have the fastest chemical reaction? A. I B. Br C. Cl D. F Which of the following element's atoms will NOT have an octet of electrons when 9 the atom is ionized? A. Li B. Na C. K D. Rb 10 What is the octet rule? A. All atoms when they chemically react will have only 8 electrons after the reaction is completed. B. Most atoms when they chemically react will try to have 8 valence electrons after the reaction is completed. C. Most atoms when they chemically react will give 8 valence electrons to another atom. D. Most atoms when they chemically react will take 8 valence electrons from another atom. BLIVEWORKSHEETS

Y For parts a to f, consider the loss of electrons by atoms of the element X, and a gain of electrons by atoms of the element Y, if X is in Group 2A (2), Period 3, and Y is in Group 7A (17), Period 3. a. Which reactant has higher electronegativity? b. What are the ionic charges of X and Y? c. Write the electron arrangements for the atoms of X and Y. d. Write the electron arrangements for the ions of X and Y. e. Give the names for the noble gases with the same electron arrangements as the X and Y ions. f. Write the formula and name for the ionic compound formed from X and Y. e. a) Y has the higher electronegativity b)

In drawing Lewis structures what does octet rule mean? O a. atoms lose electrons until they have only 8 electrons left O b. atoms are stable if they have 8 p electrons OC. Atoms are the most stable if they have 8 valence electrons

1. Compare the lattice energies of Cao and Mg0 by: a. Writing out the reaction equation associated with the lattice energy for MgO. b. Using Coulomb's Law to clearly and completely explain the difference between MgO and Cao lattice energies in terms of specific scientific principles as discussed in lecture. 2. Write the correct formula for the following ionic compounds: a. Aluminum Acetate b. Ammonium Sulfate C. Calcium Phosphate 3. Draw the complete Lewis structures for each of the following; be sure to include all nonzero formal charges and resonance structures if applicable. a. SCN lon (hint add one additional valence electron for-1 lons) b. Co: ion (hint: add two additional valence electrons for -2 ions) C OF d. PH3 e. CH;CH; f. N;Ha

Suppose a chemist discovers a new metallic element and names it "Xhaustium" (Xh).Xh exhibits chemical behaviour similar to an alkaline earth. Xh(s) + F2(g) → XhF2(s)   Lattice energy for XhF2 -2140. kJ/mol First Ionization energy of Xh  310. kJ/mol Second Ionization energy of Xh  589 kJ/mol Electron affinity of F -327.8 kJ/mol Bond energy of F2  154 kJ/mol Enthalpy of sublimation (atomization) of Xh      150. kJ/mol Use the above data to calculate ΔH°f for Xhaustium fluoride. Your answer must be accurate and precise to the nearest 1 kJ/mol, as are the given parameters.

refer to pic Which of the following is NOT bent? Select one: a.O3 b.NO2– c.SO2 d.SiO2

1) What do you predict the average bond length and average bond energy values for the F-F bond based on the chart below?  WIll it be higher than, lower than, or the same as the other bonds shown in the chart.  Justify your answer. Bond Average Bond Length (PM) Average Bond Energy (KJ/MOLE) CL-CL 199 243 Br-Br 228 193 I-I 267 151   2) Explain how a stable covalent bond is formed in terms of attractive and repulsive forces.   Note: Please briefly explain, Thank you.

Which of the following(s) are true? Select one or more: O a. Chlorofluorocarbons are natural molecules formed by mixing of reactive species in the mesosphere. O b. CFCS release halogen atoms through photodissociation in the upper atmosphere. O c. In the polar winter, a vortex develops which isolates cold air over the pole. O d. One atom of chlorine can destroy only one ozone molecule. O e. Hydrogen chloride and chlorine nitrate (CIONO2) are halogen reservoirs in the atmosphere

Question 8 please

d. The energy required to separate the ions in the calcium carbonate crystal lattice into individual calcium and carbonate ions as represented in the table below is known as the lattice energy. As shown in the table, the lattice energy of magnesium carbonate is more than the lattice energy of calcium carbonate. Explain why in terms of periodic properties and Coulomb's law.