Contrast the general physical state at room temperature and room pressure for ionic and molecular compounds.

How many “electron dots” should appear in the Lewis structures for each of the following polyatomic ions?

a. $\text{PO}_3^{3-}$

b. $\text{PO}_4^{3-}$

c. $\text{H}_3\text{O}^+$

d. $\text{BrO}_4^{-}$

How many “electron dots” should appear in the Lewis structures for each of the following polyatomic ions?

a. $\text{ClO}^{-}$

b. $\text{ClO}_2^{-}$

c. $\text{S}_2^{2-}$

d. $\text{NH}_4^{+}$

Match each of the listed restrictions on variables to the following gas laws: Boyle’s law, Charles’s law, and the combined gas law. More than one answer may be correct in a given situation. a. The number of moles is constant. b. The temperature is constant.

Indicate whether each of the following statements relating to the compound nitric oxide (NO) is true or false.

a. NO is a very flammable, colorless gas.

b. Lightning passing through air produces small amounts of NO.

c. NO is present in automobile exhaust.

d. NO is a precursor for both photochemical smog and acid rain.

Draw Lewis structures to illustrate the bonding in the following molecules. In each case, there will be at least one multiple bond present in a molecule.

a. $\text{COCl}_2$: Both chlorine atoms and the oxygen atom are bonded to the carbon atom.

b. $\text{C}_2\text{H}_2\text{Br}_2$: The two carbon atoms are bonded to one another. Each carbon atom also has a bromine atom and a hydrogen atom bonded to it.

c. $\text{C}_2\text{N}_2$: The two carbon atoms are bonded to one another, and each carbon atom also has a nitrogen bonded to it.

d. $\text{CH}_2\text{N}_2$: A central carbon atom has both nitrogen atoms bonded to it. Both hydrogen atoms are bonded to one of the two nitrogen atoms.

Indicate whether each of the following statements relating to the compound nitric oxide (NO) is true or false.

a. Two unpaired electrons are present in the NO molecule.

b. NO does not occur in nature but is easily prepared in the laboratory.

c. $\text{N}_2$ and $\text{O}_2$ are the reactants needed for formation of NO.

d. The source for NO present in the human body is inhalation of polluted air.

Draw Lewis structures to illustrate the bonding in the following molecules. In each case, there will be at least one multiple bond present in a molecule.

a. $\text{C}_3\text{H}_4$: A central carbon atom has two other carbon atoms bonded to it. Each of the noncentral carbon atoms also has two hydrogen atoms bonded to it.

b. $\text{N}_2\text{F}_2$: The two nitrogen atoms are bonded to one another, and each nitrogen atom also has a fluorine atom bonded to it.

c. $\text{C}_2\text{H}_3\text{N}$: The two carbon atoms are bonded to each other. One of the carbon atoms has a nitrogen atom bonded to it, and the other carbon atom has three hydrogen atoms bonded to it.

d. $\text{C}_3\text{H}_4$: A central carbon atom has two other carbon atoms bonded to it. One of the noncentral carbon atoms also has one hydrogen atom bonded to it, and the other one has three hydrogen atoms bonded to it.

Contrast the basic structural unit in ionic and molecular compounds.

Draw Lewis structures for the simplest molecular compound likely to form between these pairs of elements.

a. Nitrogen and chlorine b. Bromine and hydrogen c. Phosphorus and fluorine d. Selenium and bromine

Draw Lewis structures for the simplest molecular compound likely to form between these pairs of elements. a. Sulfur and fluorine b. Carbon and iodine c. Nitrogen and bromine d. Selenium and hydrogen

Draw Lewis structures to illustrate the covalent bonding in the following polyatomic molecules. The first atom in each formula is the central atom to which all other atoms are bonded.

a. $\text{AsH}_3$ b. $\text{AsCl}_3$ c. $\text{CBr}_4$ d. $\text{SCl}_2$

Identify the coordinate covalent bond(s) present, if any, in each of the following molecules by listing the two atoms involved in the bond. Name the atom on the left or the bottom in the bond first.

a. $: \mathrm{N} \equiv \mathrm{N}-\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{O}}}\hspace{0.05cm}\colon$

b. $\mathrm{H}-\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{O}}}\hspace{0.05cm}-\hspace{-0.05 cm}\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{F}}}\hspace{0.05cm}\colon$

c. $:\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{O}}}\hspace{0.05cm}-\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{Cl}}}\hspace{0.05cm}-\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{O}}}\hspace{0.05cm}-\mathrm{H}$

d. $:\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{O}}}\hspace{0.05cm}-\underset{\large{\underset{\large\colon\underset{\large{\sdot\sdot}}{{\mathrm{O}}}\hspace{0.05cm}\colon}{\mid}}}{\overset{\large{\sdot\sdot}}{\mathrm{Br}}}\hspace{0.05cm}-\underset{\large{\sdot\sdot}}{\overset{\large{\sdot\sdot}}{\mathrm{O}}}\hspace{0.05cm}-\mathrm{H}$

Draw Lewis structures for each of the following polyatomic ions. Show resonance structures, if they exist. a.

$$\mathrm { OH } ^ { - }$$

, b.

$$\mathrm { H } _ { 3 } \mathrm { C } _ { 2 } \mathrm { O } _ { 2 } ^ { - }$$

, c.

$$\mathrm { BrO } _ { 3 } ^ { - }$$