IUPAC Nomenclature and Molecular Shapes

The video tutorial covers a practice exam focusing on organic chemistry transformations, including hydrogenation of dienes and elimination of halogens. It addresses multiple-choice questions on molecular shapes and bond types, discusses hybridization and line notation, explains IUPAC nomenclature, and analyzes cyclohexane chair conformations.

What is the primary reagent used to convert a diene to an alkane?

• Reduction with lithium aluminum hydride

• Oxidation with potassium permanganate

• Hydrogenation over a transition metal catalyst

• Substitution with sodium hydroxide

Which reagent is used to ensure elimination over substitution in a haloalkane?

• Hydrochloric acid

• Tert-butoxide

• Ammonia

• Sodium hydroxide

Which compound has a trigonal pyramidal molecular shape?

• Boron trifluoride (BF3)

• Methane (CH4)

• Ammonia (NH3)

• Carbon dioxide (CO2)

What type of bond is formed between potassium and bromine in potassium bromide?

• Ionic bond

• Hydrogen bond

• Covalent bond

• Metallic bond

How can you determine the hybridization of an atom in a compound?

• By identifying the molecular shape

• By counting the number of lone pairs

• By using line notation to visualize electron domains

• By measuring the bond angles

What is the first step in IUPAC nomenclature?

• Identifying the substituents

• Determining the molecular shape

• Identifying the parent chain

• Counting the number of hydrogen atoms

In IUPAC nomenclature, which prefix is considered in alphabetical order?

• Isopropyl

• Dimethyl

• Tert-butyl

• Sec-butyl

What is the most stable conformation of a tri-substituted cyclohexane?

• Larger substituents in equatorial positions

• Larger substituents in axial positions

• All substituents in equatorial positions

• All substituents in axial positions

What is the correct IUPAC name for a compound with an ethyl group on carbon 4, an isopropyl group on carbon 6, and a methyl group on carbon 2 of a nonane?

• 4-ethyl-2-methyl-6-isopropyl nonane

• 6-isopropyl-4-ethyl-2-methyl nonane

• 4-ethyl-6-isopropyl-2-methyl nonane

• 2-methyl-4-ethyl-6-isopropyl nonane

What happens to axial and equatorial positions when a cyclohexane chair conformation is flipped?

• No change occurs

• Only axial positions change

• Only equatorial positions change

• Axial positions become equatorial and vice versa