1. carbon
2. nitrogen
3. oxygen
4. phosphorous

Correct Answer Number: 1

Explanation: In general, organic molecules contain carbon and organic chemistry is the study of carbon compounds.

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1. low melting point
2. high melting point
3. soluble in polar solvents
4. insoluble in nonpolar solvents

Correct Answer Number: 1

Explanation: High melting points (450 degrees and higher) are characteristic of ionic compounds but organic compounds generally have low melting points. Wax and street tar melt in the summer heat; sugar melts and can burn on the kitchen stove. Wax, tar, and sugar are examples of organic compounds.

1. slower because organic particles are ions
2. slower because organic particles contain covalent bonds
3. faster because organic particles are ions
4. faster because organic particles contain covalent bonds

Correct Answer Number: 2

Explanation: Most organic compounds have covalent bonds so eliminate choices 1 and 3. Covalent or shared bonds are hard to break so many organic reactions proceed slowly.

1. 1-propanol and 2-propanol
2. methanoic acid and ethanoic acid
3. methanol and methanal
4. ethane and ethanol

Correct Answer Number: 1

Explanation: By definition isomers have the same molecular formula but different structural formulas. Choice 1 compounds have the same molecular formula but the -OH group is located on the first or second carbon atoms. The other choices do not have the same molecular formulas.

1. Carbon atoms combine readily with oxygen.
2. Carbon atoms have very high electronegativity.
3. Carbon readily forms ionic bonds with other carbon atoms.
4. Carbon readily forms covalent bonds with other carbon atoms.

Correct Answer Number: 4

Explanation: Carbon forms four covalent or shared bonds with other carbon atoms as well as many other kinds of atoms. It has an almost limitless ability to bond with other carbon atoms making possible a very large number of compounds.

1. starch and nylon
2. starch and cellulose
3. protein and nylon
4. protein and plastic

Correct Answer Number: 2

Explanation: Plastic and nylon are synthetic (made in a laboratory). Starch and cellulose are natural polymers (large molecules composed of chain(s) of smaller molecules.

1. butane
2. butene
3. benzene
4. butyne

Correct Answer Number: 3

Explanation: Benzene has the formula C₆H₆ and is ring-shaped or shaped like a closed chain.
C₄H₁₀is butane and has one single carbon bond; C₄H₈ is butene and has one double carbon bond. C₄H₆ is butyne and has one triple carbon bond. Hint: there are 2 e-s in butene--double bond; one e in butane--single bond; ty can be though of as ti or short for triple bond, so butyne--triple bond. See also Table Q.

1. pyramid
2. tetrahedron
3. square
4. rectangle

Correct Answer Number: 2

Explanation: Organic compounds are three dimensional and CH₄ has 4 equivalent single bonds. Tetra means 4.

1. C₂H₂ and C₂H₆
2. C₂H₂ and C₃H₆
3. C₄H₈ and C₂H₄
4. C₆H₆ andC₇H₈

Correct Answer Number: 3

Explanation: Hydrocarbons with one double bond are alkenes, general formula C_nH_2n or twice as many hydrogen atoms as carbon atoms. Choice 3 is the only pair with both hydrocarbons having twice as many hydrogen atoms as carbon atoms. See Table Q.

1. substitution
2. addition
3. esterification
4. fermentation

Correct Answer Number: 2

Explanation: Addition usually involves adding one or more atoms at a double or triple bond. Here H₂ combines with CH₂CH₂ changing ethene (double bond) into ethane (single bond). See also #14, this topic.

1. water
2. oxygen
3. carbon dioxide
4. sulfur dioxide

Correct Answer Number: 3

Explanation: By definition fermentation is the conversion of sugar by yeast enzymes (without oxygen) into ethanol and carbon dioxide. This happens in wine and when cider turns "hard."

1. ethane
2. ethene
3. ethyne
4. ethanol

Correct Answer Number: 1

Explanation: By definition saturated hydrocarbons share a single pair of electrons (single bond). The hydrocarbon series -ane has a single bond. (-ene has a double bond; -yne has a triple bond; and alcohols have one -OH group at the end of a hydrocarbon). See Table Q.

1. an addition reaction
2. a substitution reaction
3. a saponification reaction
4. an esterification reaction

Correct Answer Number: 2

Explanation: In the above reaction, notice how a Cl atom has been substituted for one H atom. This is similar to a baseball or basketball player taking the place or substituting for another player.
See #10, this topic for an example of addition.

1. 1
2. 2
3. 3
4. 4

Correct Answer Number: 4

Explanation: Because carbon has 4 valence electrons, it can form 4 shared (covalent) bonds. Refer to the Periodic Table for the number of valence electrons in the element carbon.

1. acids
2. alcohols
3. esters
4. ethers

Correct Answer Number: 2

Explanation: Alcohols by definition have the --OH group covalently bonded to the end of a hydrocarbon (R ). See Table R: organic acids have the formula R --COOH; esters have the formula R₁--COOH--R₂; ethers have the formula R₁--O--R₂.

1. 2-methylpropane
2. 2-methylbutane
3. propane
4. butane

Correct Answer Number: 3

Explanation: Propane has 3 carbon atoms (prop- is a prefix for 3 carbon atoms). Butane has 3 + 1 or 4 carbon atoms. Methylpropane is propane with a methyl group (CH₃) in place of one of the hydrogen atoms. Therefore it also has 4 carbon atoms. See Table P.

1. ketone
2. protein
3. ester
4. acid

Correct Answer Number: 2

Explanation: Proteins are composed of amino acids (monomers) joined into long chains. See Table R.

1. boiling points
2. melting points
3. triple points
4. saturation points

Correct Answer Number: 1

Explanation: Because hydrocarbons differ in boiling points, fractional distillation separates the parts (fractions) of the mixture by heating the hydrocarbons in long columns until they form gases (vaporization). At various points in the tower the fractions (hydrocarbons) condense and are removed. This is possible because the hydrocarbons have different boiling points.

1. CH₃OH
2. CH₃OCH₃
3. CH₃COOH
4. CH₃COOCH₃

Correct Answer Number: 3

Explanation: See Ref. Table R if you forget the formula for an organic acid. CH₃COOH is found almost in the center of the table. It does help to remember that organic acids end in COOH and alcohols have OH near the end of the word. See also Ref. Table K for an example of an organic acid.