Chapter 5

Without knowing the electronegativity values, in what situation can you be absolutely sure that the bonding between two atoms will be purely covalent?

Classify the bonds in each of the following as ionic, covalent, or polar covalent. Explain each choice. (a) \(\mathrm{Br}_{2}\) (b) \(\mathrm{PCl}_{3}\) (c) LiCl (d) ClF (e) \(\mathrm{MgCl}_{2}\)

What is a binary compound? Is atmospheric oxygen an example of a binary compound?

What does the suffix -ide mean, and which element in the name of a binary ionic compound gets it?

Which element in a binary covalent compound gets the suffix -ide? Why?

Any ionic compound has an overall charge of zero. How does this fact help to determine its formula?

Consider the two binary compounds \(\mathrm{Al}_{2} \mathrm{O}_{3}\) and \(\mathrm{N}_{2} \mathrm{O}_{3}\) (a) Which is a binary ionic compound and which is a binary covalent compound? Explain. (b) \(\mathrm{Al}_{2} \mathrm{O}_{3}\) is properly named aluminum oxide, but \(\mathrm{N}_{2} \mathrm{O}_{3}\) is named dinitrogen trioxide. Explain fully why one name uses Greek prefixes and the other does not.

Give the proper name for the following binary ionic compounds: (a) \(\mathrm{Ca}_{3} \mathrm{~N}_{2}\) (b) \(\mathrm{AlF}_{3}\) (c) \(\mathrm{Na}_{2} \mathrm{O}\) (d) \(\mathrm{CaS}\)

Give the formulas of the following binary ionic compounds: (a) Calcium bromide (b) Sodium sulfide (c) Potassium nitride (d) Lithium oxide

What "monkey wrench" do transition metals throw into the picture when naming binary compounds? What do we include in the nomenclature system to accommodate them?

Give the proper name for the following compounds: (a) \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) (b) \(\left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\) (c) \(\mathrm{KClO}\) (d) \(\mathrm{CaCO}_{3}\) (e) \(\mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}\)

Give the formulas for the following compounds: (a) Ammonium acetate (b) Ammonium carbonate (c) Iron(II) nitrate (d) Ferric hydroxide (e) Calcium hypochlorite

Give the proper name for the following binary covalent compounds: (a) \(\mathrm{PCl}_{3}\) (b) \(\mathrm{SO}_{2}\) (c) \(\mathrm{N}_{2} \mathrm{O}_{4}\) (d) \(\mathrm{P}_{5} \mathrm{O}_{10}\)

Consider the sulfate, sulfite, nitrate, nitrite, chlorate, and chlorite ions. What information do the -ate and -ite suffixes communicate?

The oxide ion is \(\mathrm{O}^{2-}\). How does this ion differ from the peroxide ion, \(\mathrm{O}_{2}^{2-} ?\) Draw dot diagrams for both.

Students commonly confuse ammonia with ammonium. (a) Write the formula and draw dot diagrams for both species, and describe the difference between them. (b) Based on your answer to (a), write the formulas for phosphine and phosphonium, complete with charges if there are any.

A student writes the formula for magnesium hydroxide as \(\mathrm{MgOH}_{2}\). What is wrong with that formula? How should the student fix it?

A compound consisting of one oxygen atom and two nitrogen atoms is written \(\mathrm{N}_{2} \mathrm{O}\) and is called dinitrogen monoxide. It is not written as \(\mathrm{ON}_{2}\), and it is not called oxygen dinitride. Explain why.

\(\mathrm{N}_{2} \mathrm{O}\) is called dinitrogen monoxide, whereas, \(\mathrm{Na}_{2} \mathrm{O}\) is called sodium oxide, not disodium oxide. Explain why, and also explain how the name sodium oxide still lets us know that there are two sodium atoms in the formula.

Many acids can be thought of as anions that have an \(\mathrm{H}^{+}\) ion attached to them. Fill in the following table: \begin{tabular}{|l|l|l|l|} \hline Anion & Anion name & Acid formula & Acid name \\ \hline \(\mathrm{F}^{-}\) & & & \\ \hline \(\mathrm{NO}_{3}^{-}\) & & & \\ \hline \(\mathrm{Cl}^{-}\) & & & \\ \hline \(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}^{-}\) & & & \\ \hline \(\mathrm{NO}_{2}^{-}\) & & & \\ \hline \end{tabular}

When naming acids, when do you use the -ic suffix and when do you use the -ous suffix?

What is the name of the polyatomic ion \(\mathrm{NO}_{3}^{-} ?\) What are the names of the acids \(\mathrm{HNO}_{3}\) and \(\mathrm{HNO}_{2} ?\)

Acetic acid, sulfurous acid, and phosphoric acid can each be thought of as an anion with one or more \(\mathrm{H}^{+}\) ions attached. For each acid, how many \(\mathrm{H}^{+}\) ions have been attached to the anion?

Give the molecular formula for hypochlorous acid and perchloric acid.

What is an ionic bond? How does it differ from a covalent bond, and how is it similar to a covalent bond?

Draw dot diagrams for \(\mathrm{Cl}_{2}\) and for \(\mathrm{MgCl}_{2}\) (put \(\mathrm{Mg}\) in the middle) that agree with the type of bonding occurring in each. (That is, show electrons as being shared or transferred, and if they are transferred, show the charges of the resulting ions.)

What is a shortcut rule for determining the number of covalent bonds a representative element from group IVA, VA, VIA, VIIA, or VIIIA can form?

Why are the noble gases monatomic?

How many lone pairs of electrons are on the \(\mathrm{P}\) atom of \(\mathrm{PCl}_{3} ?\)

Draw dot diagrams for all resonance forms of the \(\mathrm{NCO}^{-}\) ion.

Which one of these four molecules contains a triple bond: \(\mathrm{F}_{2}, \mathrm{O}_{3}, \mathrm{HCN}\), or \(\mathrm{H}_{2} \mathrm{CO}\) ?

Which is the correct Lewis dot diagram for carbonyl fluoride, \(\mathrm{COF}_{2} ?\) What is wrong with the other two?

Which one of the following is expected to have resonance forms? Explain your choice. (a) \(\mathrm{NH}_{4}^{+}\) (b) HCN (c) \(\mathrm{CO}\) (d) \(\mathrm{NO}_{2}^{-}\)

How many lone pairs of electrons are there on Br in \(\mathrm{BrF}_{2}^{+} ?\)

Which of the following represents the correct resonance forms for \(\mathrm{SO}_{2} ?\) Explain what is wrong with the sets you did not choose.

Which element has the lowest electronegativity, and how can you answer this question without looking up electronegativity values? (a) \(\mathrm{Mg}\) (b) \(\mathrm{Cl}\) (c) \(\mathrm{Ca}\) (d) \(\mathrm{Br}\)

Which one of the following statements is true about \(\mathrm{BeH}_{2} ?\) (a) It is ionic with \(\mathrm{H}\) as the anion. (b) It is ionic with \(\mathrm{H}\) as the cation. (c) It has polar covalent bonds with a partial negative charge on \(\mathrm{H}\). (d) It has polar covalent bonds with a partial positive charge on \(\mathrm{H}\).

The greater the electronegativity difference between two bonded atoms, the greater the percent character of the bond.

The phosphorus atom in \(\mathrm{PCl}_{3}\) should have a (a) \(\delta^{+}\) charge (b) \(\delta^{-}\) charge (c) \(3+\) charge (d) 3 - charge Explain.

Iodine atoms in \(\mathrm{I}_{2}\) should have a (a) \(1^{-}\) charge (b) \(\delta^{-}\) charge (c) \(\delta^{+}\) charge (d) No charge

Arrange in order of increasing ionic character: \(\mathrm{CsBr}, \mathrm{KBr}, \mathrm{PBr}_{3} \mathrm{MgBr}_{2}\)

Which of the following substances are ionic and which are molecular? Name each substance. Draw Lewis dot diagrams for each molecular substance and for the anion of each ionic substance. (a) \(\mathrm{Cl}_{2}\) (b) \(\mathrm{HCl}(\mathrm{g})\) (c) \(\mathrm{NaCl}\) (d) \(\mathrm{Mg}\left(\mathrm{ClO}_{2}\right)_{2}\) (e) \(\mathrm{CH}_{3} \mathrm{OH}\) (methanol) (f) \(\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3}\) (g) \(\mathrm{Pb}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}\)

How many electrons does the nickel atom lose when forming nickel(II) nitrate? When forming nickel(II) sulfate?

Why is the oxygen atom listed first in \(\mathrm{OF}_{2}\) but last in \(\mathrm{Br}_{2} \mathrm{O} ?\)

The use of chlorofluorocarbons (CFCs) in airconditioning and refrigeration systems has been linked to depletion of the ozone layer of the atmosphere. One of the most widely used CFCs, freon-12, has the formula \(\mathrm{CF}_{2} \mathrm{Cl}_{2}\). It is now being replaced with a compound that has the formula \(\mathrm{CH}_{2} \mathrm{FCH}_{3}\). Draw the dot diagrams for \(\mathrm{CF}_{2} \mathrm{Cl}_{2}\) and \(\mathrm{C} \mathrm{H}_{2} \mathrm{FCH}_{3}\). (Hint: In \(\mathrm{CH}_{2} \mathrm{FCH}_{3}\), the carbons bond to each other, and one of them bonds to fluorine.)

Why is HF not considered an ionic compound even though its percent ionic character is greater than \(50 \%\) ?

Give the formula for (a) calcium phosphate, (b)) potassium hydrogen phosphate, (c) magnesium cyanide, (d) barium chlorate.

Give the proper name of these compounds: (a) \(\mathrm{Fe}_{2}\left(\mathrm{SO}_{3}\right)_{3}\) (b) \(\mathrm{Au}\left(\mathrm{NO}_{3}\right)_{3}\) (c) \(\mathrm{NaH}_{2} \mathrm{PO}_{4}\) (d) \(\mathrm{Pb}\left(\mathrm{CH}_{3} \mathrm{CO}_{2}\right)_{2}\)

Hydroxylamine is a compound that contains one nitrogen atom and one oxygen atom connected with a single bond. The remaining atoms are hydrogens. Predict the formula for hydroxylamine and draw its dot diagram.

Using only the periodic table, arrange these sets of atoms in order of increasing electronegativity: (a) \(\mathrm{Li}, \mathrm{Be}, \mathrm{K}\) (b) \(\mathrm{O}, \mathrm{Si}, \mathrm{S}\) (c) \(\mathrm{Br}_{t} \mathrm{I}, \mathrm{Te}\)