Quiz

QUIZ

1. Which is the correct way to describe an ether?

a. RCOOR’ b. ROR’ c. RCOR’ d. RCOH

Answer: b. The basic structure of the ether molecule is ROR’, in which two side chains are connected by an oxygen molecule.

2. Which of the following is the correct name for an ether, according to the

IUPAC nomenclature?

a. Ethoxy-methane b. tert-butoxy-ethane c. Isopropoxy-ethane d. Methoxy-ethane

Answer: d. The only correct naming structure for an ether comes when the shorter alkane is listed as the oxy group or alkoxyl side chain and the longer alkane is considered the parent compound.

3. What can be said about the boiling point of ethers?

a. It decreases with molecular mass and approaches that of alcohols of the same size. b. It decreases with molecular mass and approaches that of alkanes of the same size. c. It increases with molecular mass and approaches that of alcohols of the same size. d. It increases with molecular mass and approaches that of alkanes of the same size.

Answer: d. Boiling point will increase with molecular mass in all organic molecules; as there are no hydrogens attached to the oxygen

atoms, there will be less intermolecular binding so the boiling point is close to that of the alkane and not the alcohol of the same size.

4. There is a reaction with sulfuric acid and ethanol that will produce an ether.

What factor most drives this type of reaction?

a. Low heat b. Catalyst addition c. Sulfuric acid concentrations d. Very high heat

Answer: a. This reaction will make diethyl ether in the presence of sulfuric acid as long as the temperature is low. If the temperature is too high, the same substrates will favor an elimination reaction that will result in an alkene formation.

5. A six-membered ring that is a cyclic ether can be referred to as what molecule?

a. Oxirane b. Furan c. Tetrahydrofuran d. Pyran

Answer: d. Pyran is a six-membered ring that is a cyclic ether. It has two double bonds that can be substituted to make a more complex ringed molecule.

6. The term epoxy can be used to describe a functional group on an alkane that consists of what?

a. The cyclic arrangement of two carbon atoms plus an oxygen molecule in the chain. b. The connection of two carbon atoms by an oxygen molecule between them. c. The presence of two ketone molecules side-by-side. d. The addition of a benzene ring with an oxygen molecule attached to a carbon atom on the alkane.

Answer: a. The term epoxy refers to the cyclic arrangement of two carbon atoms plus an oxygen molecule on the chain or side chain, effectively making an oxirane out of the chain.

7. Triglycerides are what type of molecule?

a. Tri-esters b. Tri-aldehydes c. Tri-ketones d. Tri-alkenes

Answer: a. These molecules are tri-esters, combining long-chain carboxylic acids or “fatty acids) with a glycerol molecule, which is a trialcohol molecule having three carbon atoms.

8. Which boiling point will be lowest, based on having the same number of carbon atoms?

a. Alcohol b. Carboxylic acid c. Ester d. Glycerol

Answer: c. The ester will have the lowest boiling point because the others will have hydrogen bonding added to the dipole-dipole bonding and the van der Waals dispersion forces. Esters do not have the hydrogen associated with the oxygen so the boiling point will be lower.

9. Which leaving group is most likely to leave the carbonyl group in an electrophilic substitution reaction because of its electronegativity?

a. Chloride or halide b. Amide c. Acid anhydride d. Ester

Answer: a. In an acid chloride or acid halide, the chloride leaving group is the most electronegative, making it more likely to act as a leaving group when the carbonyl carbon atom is acted on by a nucleophile.

10. What is the pair of molecules necessary to make a polyester in manufacturing?

a. Alcohol plus an ester b. Two different ester molecules c. A di-alcohol and a diester d. A di-alcohol and a di-carboxylic acid

Answer: d. The polyester is identified as a di-alcohol interspersed between di-carboxylic acid molecules with a loss of water in the chemical process.