Question

question 21 of 21 (1 point) | question attempt: 2 of unlimited
structure \tname
chemical structure: benzene with br (top) and f (left) \tempty box
chemical structure: benzene with two i (para positions) \tempty box
chemical structure: benzene with two cl (ortho positions) \tempty box

Explanation:

To name these substituted benzene compounds, we use the IUPAC nomenclature for disubstituted benzenes (or use prefixes for multiple substituents) and consider the positions (ortho, meta, para) or numerical locants.

First Compound (Br and F on benzene)

The structure has a bromine (Br) and a fluorine (F) on a benzene ring, with Br at position 1 and F at position 2 (ortho - adjacent).

• The substituents are bromo (Br) and fluoro (F).
• Order of substituents: alphabetical order (bromo comes before fluoro? Wait, no—alphabetical order of the substituent names: “bromo” (B) and “fluoro” (F). Wait, no: “bromo” starts with B, “fluoro” with F. So alphabetical order is bromo first, then fluoro. But the positions: Br is at 1, F at 2 (ortho).
• Name: 1 - bromo - 2 - fluorobenzene (or o - bromofluorobenzene, but IUPAC prefers numerical locants for clarity).

Second Compound (Two Iodines on benzene)

The structure has two iodine (I) atoms on the benzene ring, at positions 1 and 4 (para - opposite).

• Substituent: iodo (I), two of them → diiodo.
• Positions: 1 and 4.
• Name: 1,4 - diiodobenzene (or p - diiodobenzene).

Third Compound (Two Chlorines on benzene)

The structure has two chlorine (Cl) atoms on the benzene ring, at positions 1 and 2 (ortho - adjacent).

• Substituent: chloro (Cl), two of them → dichloro.
• Positions: 1 and 2.
• Name: 1,2 - dichlorobenzene (or o - dichlorobenzene).

Final Answers (Filling the “name” column):

1. First row (Br and F): $\boldsymbol{1 - bromo - 2 - fluorobenzene}$ (or o - bromofluorobenzene)
2. Second row (two I): $\boldsymbol{1,4 - diiodobenzene}$ (or p - diiodobenzene)
3. Third row (two Cl): $\boldsymbol{1,2 - dichlorobenzene}$ (or o - dichlorobenzene)

Answer:

To name these substituted benzene compounds, we use the IUPAC nomenclature for disubstituted benzenes (or use prefixes for multiple substituents) and consider the positions (ortho, meta, para) or numerical locants.

First Compound (Br and F on benzene)

The structure has a bromine (Br) and a fluorine (F) on a benzene ring, with Br at position 1 and F at position 2 (ortho - adjacent).

• The substituents are bromo (Br) and fluoro (F).
• Order of substituents: alphabetical order (bromo comes before fluoro? Wait, no—alphabetical order of the substituent names: “bromo” (B) and “fluoro” (F). Wait, no: “bromo” starts with B, “fluoro” with F. So alphabetical order is bromo first, then fluoro. But the positions: Br is at 1, F at 2 (ortho).
• Name: 1 - bromo - 2 - fluorobenzene (or o - bromofluorobenzene, but IUPAC prefers numerical locants for clarity).

Second Compound (Two Iodines on benzene)

The structure has two iodine (I) atoms on the benzene ring, at positions 1 and 4 (para - opposite).

• Substituent: iodo (I), two of them → diiodo.
• Positions: 1 and 4.
• Name: 1,4 - diiodobenzene (or p - diiodobenzene).

Third Compound (Two Chlorines on benzene)

The structure has two chlorine (Cl) atoms on the benzene ring, at positions 1 and 2 (ortho - adjacent).

• Substituent: chloro (Cl), two of them → dichloro.
• Positions: 1 and 2.
• Name: 1,2 - dichlorobenzene (or o - dichlorobenzene).

Final Answers (Filling the “name” column):

1. First row (Br and F): $\boldsymbol{1 - bromo - 2 - fluorobenzene}$ (or o - bromofluorobenzene)
2. Second row (two I): $\boldsymbol{1,4 - diiodobenzene}$ (or p - diiodobenzene)
3. Third row (two Cl): $\boldsymbol{1,2 - dichlorobenzene}$ (or o - dichlorobenzene)