The CH3- group, which has one fewer hydrogen atom than the simplest alkane, is called a methyl group.
Missing Word
methyl
A methyl group is the one-carbon alkyl group derived from CH4. It appears as a branch in names such as 2-methylbutane.
Category: Alkanes
Question 2
Adding H2 across the double bond of an alkene over a nickel or platinum catalyst is called hydrogenation.
Missing Word
hydrogenation
Hydrogenation is an addition reaction that converts an alkene into an alkane. It is used to turn liquid vegetable oils into solid fats.
Category: Alkenes and Alkynes
Question 3
Yeast convert sugars such as glucose into ethanol and carbon dioxide by the process of fermentation.
Missing Word
fermentation
Fermentation is the anaerobic breakdown of sugar by yeast. It produces the ethanol in wine and beer.
Category: Alcohols and Ethers
Question 4
The -COOH functional group that gives organic acids their acidity is the carboxyl group.
Missing Word
carboxyl
The carboxyl group combines a carbonyl and a hydroxyl on the same carbon. Its O-H hydrogen can ionize, making carboxylic acids weak acids.
Category: Carbonyl Compounds
Question 5
Hydrocarbons that contain a benzene ring, with its delocalized pi electrons, are described as aromatic.
Missing Word
aromatic
Aromatic compounds contain a ring like benzene in which pi electrons are shared over the whole ring. This delocalization makes the ring unusually stable.
Category: Aromatic Compounds
Question 6
The specific addition reaction in which water adds across the double bond of ethene to make ethanol is called hydration.
Missing Word
hydration
Hydration adds H and OH from water across a double bond, usually with an acid catalyst. It is a major industrial route to ethanol.
Category: Alkenes and Alkynes
Question 7
The three-carbon alkane with formula C3H8, widely sold as a bottled fuel, is propane.
Missing Word
propane
Propane is the alkane with three carbons. The prefix prop- indicates three carbons and the ending -ane indicates only single bonds.
Category: Alkanes
Question 8
Butane and its branched form share the formula C4H10 but differ in structure, so the two compounds are isomers.
Missing Word
isomers
Isomers have the same molecular formula but different arrangements of atoms. Butane and 2-methylpropane are structural isomers with different boiling points.
Category: Alkanes
Question 9
Each molecule of the straight-chain alkane pentane contains 12 hydrogen atoms.
Missing Word
12
Alkanes follow CnH2n+2. For pentane, n = 5, so the number of hydrogen atoms is 2(5) + 2 = 12, giving C5H12.
Category: Alkanes
Question 10
An alkane whose carbon atoms are joined in a ring is named with the prefix cyclo.
Missing Word
cyclo
The prefix cyclo marks a ring structure, as in cyclohexane, C6H12. Cycloalkanes have two fewer hydrogens than the open-chain alkane with the same number of carbons.
Category: Alkanes
Question 11
Ethyne, the simplest alkyne and the fuel of welding torches, is commonly called acetylene.
Missing Word
acetylene
Acetylene is the common name for ethyne, HCCH. It burns with oxygen at a very high temperature, which makes it useful for welding and cutting metal.
Category: Alkenes and Alkynes
Question 12
Amines can be thought of as organic derivatives of ammonia in which carbon groups replace one or more hydrogen atoms.
Missing Word
ammonia
Ammonia, NH3, is the parent of the amines. Replacing one, two or three of its hydrogens with carbon groups gives primary, secondary and tertiary amines, which keep the nitrogen lone pair.
Category: Amines and Amides
Question 13
Natural gas consists mostly of methane, the simplest alkane, with formula CH4.
Missing Word
methane
Methane is the one-carbon alkane. It is the principal component of natural gas and burns to form carbon dioxide and water.
Category: Alkanes
Question 14
Careful oxidation of a primary alcohol, stopped before the acid forms, yields an aldehyde.
Missing Word
aldehyde
An aldehyde has a carbonyl group with at least one hydrogen on the carbonyl carbon. Further oxidation would convert it into a carboxylic acid, so the reaction must be controlled.
Category: Carbonyl Compounds
Question 15
The heterocyclic amine whose six-membered ring resembles benzene but has a nitrogen atom in place of one CH unit is pyridine.
Missing Word
pyridine
Pyridine, C5H5N, is a heterocyclic amine with an aromatic ring. Its nitrogen lone pair makes it a weak base.
Category: Amines and Amides