coschemistry / Lesson 6-05 Naming Alkanes - Free Printable

Problem Overview:

The task involves identifying the names, functional groups, and structural formulas of various organic compounds. The provided image contains a table with columns for "Name / Functional Group," "Formula," and "Structural Formula." The goal is to correctly fill in the missing information based on the given structural formulas.

Solution Explanation:

#### Step 1: Understand the Structural Formulas
Each row in the table provides a structural formula, which must be analyzed to determine the name and functional group of the compound. Here's how we approach each row:

---

#### Row 1: n-butane
- Structural Formula:
\[
\text{H}_3\text{C}-\text{CH}_2-\text{CH}_2-\text{CH}_3
\]
- Analysis:
This is a straight-chain alkane with four carbon atoms. The prefix "n-" indicates it is normal (unbranched).
- Name: \( n\)-butane
- Formula: \( \text{C}_4\text{H}_{10} \)
- Functional Group: None (alkane)

---

#### Row 2: 2-butanol
- Structural Formula:
\[
\text{H}_3\text{C}-\text{CH}(\text{OH})-\text{CH}_2-\text{CH}_3
\]
- Analysis:
This is an alcohol (functional group: -OH) where the hydroxyl group is attached to the second carbon of a butane chain.
- Name: 2-butanol
- Formula: \( \text{C}_4\text{H}_{10}\text{O} \)
- Functional Group: Alcohol (-OH)

---

#### Row 3: trans-2-butene
- Structural Formula:
\[
\text{H}_3\text{C}=\text{CH}-\text{CH}_2-\text{CH}_3
\]
- Analysis:
This is an alkene (functional group: C=C) with a double bond between the second and third carbons. The "trans" configuration means the substituents (methyl groups) are on opposite sides of the double bond.
- Name: trans-2-butene
- Formula: \( \text{C}_4\text{H}_8 \)
- Functional Group: Alkene (C=C)

---

#### Row 4: Butyne
- Structural Formula:
\[
\text{HC}≡\text{C}-\text{CH}_2-\text{CH}_3
\]
- Analysis:
This is an alkyne (functional group: C≡C) with a triple bond between the first and second carbons.
- Name: Butyne
- Formula: \( \text{C}_4\text{H}_6 \)
- Functional Group: Alkyne (C≡C)

---

#### Row 5: 1,3-Butadiene
- Structural Formula:
\[
\text{CH}_2=\text{CH}-\text{CH}=\text{CH}_2
\]
- Analysis:
This is a diene (two double bonds) with alternating single and double bonds. The numbering starts from the left, so the double bonds are at positions 1 and 3.
- Name: 1,3-Butadiene
- Formula: \( \text{C}_4\text{H}_6 \)
- Functional Group: Diene (two C=C bonds)

---

#### Row 6: Cyclopentane
- Structural Formula:
\[
\text{C}_5\text{H}_{10}
\]
- Analysis:
This is a cyclic alkane with five carbon atoms forming a ring.
- Name: Cyclopentane
- Formula: \( \text{C}_5\text{H}_{10} \)
- Functional Group: None (cyclic alkane)

---

#### Row 7: cis-2-butene
- Structural Formula:
\[
\text{H}_3\text{C}-\text{CH}=\text{CH}-\text{CH}_3
\]
- Analysis:
This is an alkene with a double bond between the second and third carbons. The "cis" configuration means the substituents (methyl groups) are on the same side of the double bond.
- Name: cis-2-butene
- Formula: \( \text{C}_4\text{H}_8 \)
- Functional Group: Alkene (C=C)

---

#### Row 8: trans-2-butene
- Structural Formula:
\[
\text{H}_3\text{C}-\text{CH}=\text{CH}-\text{CH}_3
\]
- Analysis:
This is an alkene with a double bond between the second and third carbons. The "trans" configuration means the substituents (methyl groups) are on opposite sides of the double bond.
- Name: trans-2-butene
- Formula: \( \text{C}_4\text{H}_8 \)
- Functional Group: Alkene (C=C)

---

#### Row 9: Methyl ethyl ether
- Structural Formula:
\[
\text{H}_3\text{C}-\text{O}-\text{CH}_2-\text{CH}_3
\]
- Analysis:
This is an ether (functional group: O) where one oxygen atom is bonded to a methyl group and an ethyl group.
- Name: Methyl ethyl ether
- Formula: \( \text{C}_3\text{H}_8\text{O} \)
- Functional Group: Ether (O)

---

Final Answer:

The completed table is as follows:

| Name / Functional Group | Formula | Structural Formula |
|----------------------------------|-----------------|------------------------------------------------------------------------------------|
| \( n \)-butane | \( \text{C}_4\text{H}_{10} \) | \(\text{H}_3\text{C}-\text{CH}_2-\text{CH}_2-\text{CH}_3\) |
| 2-butanol | \( \text{C}_4\text{H}_{10}\text{O} \) | \(\text{H}_3\text{C}-\text{CH}(\text{OH})-\text{CH}_2-\text{CH}_3\) |
| trans-2-butene | \( \text{C}_4\text{H}_8 \) | \(\text{H}_3\text{C}=\text{CH}-\text{CH}_2-\text{CH}_3\) |
| Butyne | \( \text{C}_4\text{H}_6 \) | \(\text{HC}≡\text{C}-\text{CH}_2-\text{CH}_3\) |
| 1,3-Butadiene | \( \text{C}_4\text{H}_6 \) | \(\text{CH}_2=\text{CH}-\text{CH}=\text{CH}_2\) |
| Cyclopentane | \( \text{C}_5\text{H}_{10} \) | \(\text{C}_5\text{H}_{10}\) |
| cis-2-butene | \( \text{C}_4\text{H}_8 \) | \(\text{H}_3\text{C}-\text{CH}=\text{CH}-\text{CH}_3\) |
| trans-2-butene | \( \text{C}_4\text{H}_8 \) | \(\text{H}_3\text{C}-\text{CH}=\text{CH}-\text{CH}_3\) |
| Methyl ethyl ether | \( \text{C}_3\text{H}_8\text{O} \) | \(\text{H}_3\text{C}-\text{O}-\text{CH}_2-\text{CH}_3\) |

\boxed{\text{See the completed table above.}}