Solved Naming Alkanes - Worksheet #1 Name the following | Chegg.com - Free Printable

To solve the problem of naming the branched alkanes, we need to follow the IUPAC (International Union of Pure and Applied Chemistry) nomenclature rules for organic compounds. Here's a step-by-step explanation for each compound:

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General Rules for Naming Branched Alkanes:

1. Identify the longest continuous carbon chain (this determines the base name).
2. Number the carbon atoms in the chain starting from the end that gives the lowest numbers to the substituents.
3. Identify and name the substituents (branches attached to the main chain).
4. List the substituents alphabetically in the final name.
5. Use locants to indicate the position of each substituent on the main chain.

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Solution for Each Compound:

#### 1.
```
H3C—CH—CH3
|
CH3
```
- Longest chain: 3 carbons → Propane
- Substituent: Methyl group (CH3) at position 2
- Name: 2-Methylpropane

#### 2.
```
H3C—CH—CH3
|
CH2—CH3
```
- Longest chain: 4 carbons → Butane
- Substituent: Ethyl group (CH2CH3) at position 2
- Name: 2-Ethylbutane

#### 3.
```
H3C—CH2—CH2—CH—CH2—CH3
|
CH2—CH3
```
- Longest chain: 6 carbons → Hexane
- Substituent: Ethyl group (CH2CH3) at position 4
- Name: 4-Ethylhexane

#### 4.
```
H3C—CH2—CH2—CH—CH2—CH3
|
CH2—CH3
|
CH3
```
- Longest chain: 7 carbons → Heptane
- Substituents:
- Methyl group (CH3) at position 4
- Ethyl group (CH2CH3) at position 4
- Name: 4-Ethyl-4-methylheptane

#### 5.
```
H3C—CH2—CH—CH2—CH—CH2—CH3
| |
CH3 CH2—CH3
```
- Longest chain: 7 carbons → Heptane
- Substituents:
- Methyl group (CH3) at position 3
- Ethyl group (CH2CH3) at position 5
- Name: 3-Methyl-5-ethylheptane

#### 6.
```
H3C—CH2—CH2—CH2—CH2—CH2
|
CH2
|
CH3
H3C—CH2—CH2—CH2—CH2—CH—CH3
|
CH3
```
- Longest chain: 8 carbons → Octane
- Substituents:
- Two methyl groups (CH3) at positions 4 and 5
- Name: 4,5-Dimethyloctane

#### 7.
```
H2C—CH—CH2—CH3
| |
CH3 CH2—CH2—CH3
|
CH3
```
- Longest chain: 6 carbons → Hexane
- Substituents:
- Two methyl groups (CH3) at position 2
- One ethyl group (CH2CH3) at position 3
- Name: 2,2-Dimethyl-3-ethylhexane

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Final Answers:

1. 2-Methylpropane
2. 2-Ethylbutane
3. 4-Ethylhexane
4. 4-Ethyl-4-methylheptane
5. 3-Methyl-5-ethylheptane
6. 4,5-Dimethyloctane
7. 2,2-Dimethyl-3-ethylhexane

---

Boxed Final Answer:

\[
\boxed{
\begin{array}{ll}
1. & \text{2-Methylpropane} \\
2. & \text{2-Ethylbutane} \\
3. & \text{4-Ethylhexane} \\
4. & \text{4-Ethyl-4-methylheptane} \\
5. & \text{3-Methyl-5-ethylheptane} \\
6. & \text{4,5-Dimethyloctane} \\
7. & \text{2,2-Dimethyl-3-ethylhexane} \\
\end{array}
}
\]