Compute the empirical and molecular formulas for each of the following elemental analyses. In each case, propose at least one structure that fits the molecular formula.

Make a model of propane (C₃H₈), and draw this model using dashed lines and wedges to represent bonds going back and coming forward.

Predict the hybridization of the oxygen atom in water, H₂O. Draw a picture of its three-dimensional structure, and explain why its bond angle is 104.5°.

The electrostatic potential maps for ammonia and water are shown here. The structure of ammonia is shown within its EPM. Note how the lone pair creates a region of high electron potential (red), and the hydrogens are in regions of low electron potential (blue). Show how your three-dimensional structure of water corresponds with its EPM.

Predict the hybridization, geometry, and bond angles for the central atoms in

a. but-2-ene, CH₃CH=CHCH₃

Predict the hybridization, geometry, and bond angles for the central atoms in

b. CH₃CH=NH

Predict the hybridization, geometry, and bond angles for the carbon and nitrogen atoms in acetonitrile (CH₃–C≡N:).

For each pair of structures, determine whether they represent different compounds or a single compound.

Two compounds with the formula CH₃–CH=N–CH₃ are known.

b. What two compounds have this formula?

c. Explain why only one compound with the formula (CH₃)₂CNCH₃ is known.

Which of the following compounds show cis-trans isomerism? Draw the cis and trans isomers of those that do.

(a) CHF=CHF

(b) F₂C=CH₂

(c) CH₂=CH–CH₂–CH₃

Give the relationship between the following pairs of structures. The possible relationships are:

same compound

constitutional isomers (structural isomers)

cis-trans isomers

not isomers (different molecular formula)

(a)

(b)

(c)

Give the relationship between the following pairs of structures. The possible relationships are:

same compound

constitutional isomers (structural isomers)

cis-trans isomers

not isomers (different molecular formula)

(g) CH₃–CH₂–CH₂–CH₃ and CH₃–CH=CH–CH₃

(h) CH₂=CH–CH₂CH₂CH₃ and CH₃–CH=CH–CH₂CH₃

(i) CH₂=CHCH₂CH₂CH₃ and CH₃CH₂CH₂CH=CH₂

Give the relationship between the following pairs of structures. The possible relationships are:

same compound

constitutional isomers (structural isomers)

cis-trans isomers

not isomers (different molecular formula)

(j)

(k)

a. Draw the resonance forms for SO₂ (bonded O–S–O).

b. Draw the resonance forms for ozone (bonded O–O–O)

c. Sulfur dioxide has one more resonance form than ozone. Explain why this structure is not possible for ozone.

Name the element that corresponds to each electronic configuration.

a. 1s² 2s² 2p²

b. 1s² 2s² 2p⁴

c. 1s² 2s² 2p⁶ 3s² 3p³

d. 1s² 2s² 2p⁶ 3s² 3p⁵

There is a small portion of the periodic table that you must know to do organic chemistry. Construct this part from ­memory, using the following steps.

a. From memory, make a list of the elements in the first two rows of the periodic table, together with their numbers of valence electrons

b. Use this list to construct the first two rows of the periodic table.

c. Organic compounds often contain sulfur, phosphorus, chlorine, bromine, and iodine. Add these elements to your ­periodic table.

For each compound, state whether its bonding is covalent, ionic, or a mixture of covalent and ionic.

a. NaCl

b. NaOH

c. CH₃Li

d. CH₂Cl₂

e. NaOCH₃

f. HCO₂Na

g. CF₄

Both PCl₃ and PCl₅ are stable compounds. Draw Lewis structures for these two compounds.

Draw a Lewis Structure for each species.

a. N₂H₄

b. N₂H₂

c. (CH₃)₂NH₂Cl

d. CH₃CN

Draw a Lewis Structure for each species.

e. CH₃CHO

f. CH₃S(O)CH₃

g. H₂SO₄

h. CH₃NCO

Draw a Lewis Structure for each species.

i. CH₃OSO₂OCH₃

j. CH₃C(NH)CH₃

k. (CH₃)₃CNO

Draw a Lewis structure for each compound. Include all nonbonding pairs of electrons.

a. CH₃COCH₂CHCHCOOH

b. NCCH₂COCH₂CHO

Draw a line-angle formula for each compound.

a. CH₃COCH₂CHCHCOOH

b. NCCH₂COCH₂CHO

Draw a line-angle formula for each compound.

c. CH₂CHCH(OH)CH₂CO₂H

d. CH₂CHC(CH₃)CHCOOCH₃

Draw Lewis structures for

a. two compounds of formula C₄H₁₀

b. two compounds of formula C₂H₆O

Draw a complete structural formula and a condensed structural formula for

a. three compounds of formula C₃H₈O

Draw a complete structural formula and a condensed structural formula for

b. five compounds of formula C₃H₆O

Some of the following molecular formulas correspond to stable compounds. When possible, draw a stable structure for each formula. Propose a general rule for the numbers of hydrogen atoms in stable hydrocarbons.

Draw complete Lewis structures, including lone pairs, for the following compounds.

(a)

(b)

(c)