Sure! Let’s go step by step through the IUPAC naming for each molecule. I’ll the logic as we go, so can apply these rules yourself! --- ## **Step-by-Step IUPAC Naming** ### **General Rules** 1. **Find the longest carbon chain** (parent chain). 2. **Number the chain** so substituents get the lowest possible numbers. 3. **Name and number substituents** (prefixes: methyl, ethyl, etc.). 4. **Alphabetize substituents** in the name. 5. **Use prefixes** (di-, tri-, etc.) for multiple identical substituents. --- ## **1. First Structure** - **Longest chain:** 5 carbons → pentane - **Substituents:** 2 methyl groups on C2 and C4 - **Numbering:** from left to right, methyls on 2 and 4 - **Name:** **2,4-dimethylpentane** --- ## **2. Second Structure** - **Parent:** Cyclohexane (6-membered ring) - **Substituents:** Three methyls and one ethyl - **Numbering:** Number ring to give lowest numbers to substituents. Start at one methyl and go around to minimize numbers. - **Result:** Methyls at 1,3,4 and ethyl at 1 - **Name:** **1-ethyl-1,3,4-trimethylcyclohexane** --- ## **3. Third Structure** - **Longest chain:** 6 carbons → hexane - **Substituents:** Methyl groups on 2, 3, and 4, plus an ethyl on 3 - **Numbering:** Number from left for lowest substituent numbers. - **Name:** **3-ethyl-2,3,4-trimethylhexane** --- ## **4. Fourth Structure** - **Parent:** Cycloheptane (7-membered ring) - **Substituents:** Ethyl on 1, methyls on 1, 3, 4 - **Numbering:** Start at ethyl (priority for alphabetization) - **Name:** **1-ethyl-1,3,4-trimethylcycloheptane** --- ## **5. Fifth Structure** - **Parent:** Cyclopropane (3-membered ring) - **Substituents:** Ethyl and propyl groups - **Numbering:** Ethyl at 1, propyl at 2 - **Name:** **1-ethyl-2-propylcyclopropane** --- ## **6. Sixth Structure** - **Longest chain:** 8 carbons → octane - **Substituents:** 4-ethyl, 6-methyl - **Numbering:** Number to give lowest numbers to substituents. - **Name:** **4-ethyl-6-methyloctane** --- ## **7. Seventh Structure** - **Longest chain:** 8 carbons → octane - **Substituents:** 3,4,5,6-tetramethyl, 5-ethyl - **Numbering:** Start from left for lowest numbers. - **Name:** **5-ethyl-3,4,5,6-tetramethyloctane** --- # **Summary Table** | # | Structure Description | IUPAC Name | |---|----------------------|------------| | 1 | 5C chain, 2 Me | 2,4-dimethylpentane | | 2 | Cyclohexane, 3 Me, 1 Et | 1-ethyl-1,3,4-trimethylcyclohexane | | 3 | 6C chain, 3 Me, 1 Et | 3-ethyl-2,3,4-trimethylhexane | | 4 | Cycloheptane, 3 Me, 1 Et | 1-ethyl-1,3,4-trimethylcycloheptane | | 5 | Cyclopropane, 1 Et, 1 Pr | 1-ethyl-2-propylcyclopropane | | 6 | 8C chain, 1 Et, 1 Me | 4-ethyl-6-methyloctane | | 7 | 8C chain, 4 Me, 1 Et | 5-ethyl-3,4,5,6-tetramethyloctane | --- If you want a detailed walk-through of any specific structure, let me know!