Solved Name the alkane Name the alkenes Name the alkynes | Chegg.com - Free Printable

To solve the problem, we need to name each of the given organic compounds based on their structure. Let's go through each category step by step.

---

1. Name the alkane

The given structure is:
```
CH3
|
CH3-CH-CH2-CH3
```

#### Steps:
1. Count the carbon atoms: There are 5 carbon atoms.
2. Identify the parent chain: The longest continuous chain is pentane (5 carbons).
3. Locate the substituents: There is a methyl group (CH3) on the second carbon.
4. Number the chain: Start numbering from the end that gives the lowest number to the substituent. Here, the methyl group is on C-2.
5. Name the compound: The name is 2-methylpentane.

Answer: 2-Methylpentane

---

2. Name the alkenes

#### First structure:
```
CH3-CH=CH-CH3
```

#### Steps:
1. Count the carbon atoms: There are 4 carbon atoms.
2. Identify the parent chain: The longest continuous chain with a double bond is butene (4 carbons).
3. Locate the double bond: The double bond is between C-2 and C-3.
4. Name the compound: The name is 2-butene.

#### Second structure:
```
CH3-CH=CH-CH2-CH3
```

#### Steps:
1. Count the carbon atoms: There are 5 carbon atoms.
2. Identify the parent chain: The longest continuous chain with a double bond is pentene (5 carbons).
3. Locate the double bond: The double bond is between C-2 and C-3.
4. Name the compound: The name is 2-pentene.

Answers:
- First structure: 2-Butene
- Second structure: 2-Pentene

---

3. Name the alkynes

#### First structure:
```
CH3-CH2-C≡C-CH3
```

#### Steps:
1. Count the carbon atoms: There are 5 carbon atoms.
2. Identify the parent chain: The longest continuous chain with a triple bond is pentyne (5 carbons).
3. Locate the triple bond: The triple bond is between C-3 and C-4.
4. Name the compound: The name is 3-pentyne.

#### Second structure:
```
CH3-CH2-C≡C-CH2-CH3
```

#### Steps:
1. Count the carbon atoms: There are 6 carbon atoms.
2. Identify the parent chain: The longest continuous chain with a triple bond is hexyne (6 carbons).
3. Locate the triple bond: The triple bond is between C-3 and C-4.
4. Name the compound: The name is 3-hexyne.

Answers:
- First structure: 3-Pentyne
- Second structure: 3-Hexyne

---

4. Name the cycloalkanes

#### First structure:
```
CH3
/ \
CH2-CH2-CH2
\ /
CH3
```

#### Steps:
1. Identify the ring: The ring has 5 carbon atoms, so it is cyclopentane.
2. Locate the substituent: There is a methyl group (CH3) on one of the carbons.
3. Name the compound: The name is methylcyclopentane.

#### Second structure:
```
CH3
/ \
CH2-CH2-CH2-CH2-CH2-CH2-CH3
\ /
CH3
```

#### Steps:
1. Identify the ring: The ring has 6 carbon atoms, so it is cyclohexane.
2. Locate the substituent: There is a propyl group (CH3-CH2-CH2-) attached to the ring.
3. Name the compound: The name is propylcyclohexane.

Answers:
- First structure: Methylcyclopentane
- Second structure: Propylcyclohexane

---

5. Name the cycloalkenes

#### First structure:
```
CH3
/ \
CH2-CH=CH-CH2
\ /
CH3
```

#### Steps:
1. Identify the ring: The ring has 5 carbon atoms, so it is cyclopentene.
2. Locate the substituent: There is a methyl group (CH3) on one of the carbons.
3. Name the compound: The name is methylcyclopentene.

#### Second structure:
```
CH3
/ \
CH2-CH=CH-CH2-CH2-CH2-CH2-CH2-CH2-CH3
\ /
CH3
```

#### Steps:
1. Identify the ring: The ring has 6 carbon atoms, so it is cyclohexene.
2. Locate the substituent: There is an octyl group (CH3-(CH2)7-) attached to the ring.
3. Name the compound: The name is octylcyclohexene.

Answers:
- First structure: Methylcyclopentene
- Second structure: Octylcyclohexene

---

6. Name the ketones

#### First structure:
```
CH3-CH2-CO-CH3
```

#### Steps:
1. Identify the functional group: The compound has a ketone group (C=O) between two carbon atoms.
2. Count the carbon atoms: There are 4 carbon atoms in the longest chain.
3. Locate the ketone group: The ketone group is on C-2.
4. Name the compound: The name is 2-butanone (or butan-2-one).

#### Second structure:
```
CH3-CH2-CO-CH(CH3)2
```

#### Steps:
1. Identify the functional group: The compound has a ketone group (C=O) between two carbon atoms.
2. Count the carbon atoms: There are 5 carbon atoms in the longest chain.
3. Locate the ketone group: The ketone group is on C-2.
4. Locate the substituent: There is an isopropyl group (CH(CH3)2) on C-4.
5. Name the compound: The name is 2-methyl-4-pentanone (or pentan-2-one).

Answers:
- First structure: 2-Butanone
- Second structure: 2-Methyl-4-pentanone

---

7. Name the carboxylic acids

#### Structure:
```
CH3-CH2-COOH
```

#### Steps:
1. Identify the functional group: The compound has a carboxylic acid group (-COOH).
2. Count the carbon atoms: There are 3 carbon atoms in the longest chain.
3. Name the compound: The name is propanoic acid.

Answer: Propanoic acid

---

8. Name the aldehyde

#### Structure:
```
CH3-CH2-CH=O
```

#### Steps:
1. Identify the functional group: The compound has an aldehyde group (-CHO).
2. Count the carbon atoms: There are 3 carbon atoms in the longest chain.
3. Name the compound: The name is propanal.

Answer: Propanal

---

Final Answers:

1. Alkane: 2-Methylpentane
2. Alkenes:
- First: 2-Butene
- Second: 2-Pentene
3. Alkynes:
- First: 3-Pentyne
- Second: 3-Hexyne
4. Cycloalkanes:
- First: Methylcyclopentane
- Second: Propylcyclohexane
5. Cycloalkenes:
- First: Methylcyclopentene
- Second: Octylcyclohexene
6. Ketones:
- First: 2-Butanone
- Second: 2-Methyl-4-pentanone
7. Carboxylic acid: Propanoic acid
8. Aldehyde: Propanal

Boxed Final Answer:
\[
\boxed{
\begin{aligned}
&\text{1. 2-Methylpentane} \\
&\text{2. 2-Butene, 2-Pentene} \\
&\text{3. 3-Pentyne, 3-Hexyne} \\
&\text{4. Methylcyclopentane, Propylcyclohexane} \\
&\text{5. Methylcyclopentene, Octylcyclohexene} \\
&\text{6. 2-Butanone, 2-Methyl-4-pentanone} \\
&\text{7. Propanoic acid} \\
&\text{8. Propanal}
\end{aligned}
}
\]