Naming Alkenes Worksheet H3C-CH=CH2 H3C-CH=CH-CH3 H3C-CH2-CH=CH2 ... - Free Printable

To solve the problem of naming the alkenes shown in the image, we need to follow the IUPAC (International Union of Pure and Applied Chemistry) nomenclature rules for alkenes. Here's a step-by-step explanation of how to name each compound:

---

General Rules for Naming Alkenes:

1. Identify the parent chain:
- The longest continuous carbon chain that contains the double bond.
- The parent chain must include the double bond.

2. Number the carbon atoms:
- Start numbering from the end of the chain that gives the double bond the lowest possible number.
- The position of the double bond is indicated by the number of the first carbon atom involved in the double bond.

3. Name the substituents:
- Identify any alkyl groups or other substituents attached to the parent chain.
- List them alphabetically before the parent name.

4. Indicate the double bond:
- Use the suffix "-ene" to indicate the presence of a double bond.
- Include the position of the double bond as a prefix (e.g., "2-" for a double bond between C-2 and C-3).

5. Check for multiple substituents:
- If there are multiple substituents, use locants to specify their positions on the chain.

---

Step-by-Step Solution for Each Compound:

#### 1. First Compound:
```
H3C
|
H3C-C=C-C-CH3
|
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 4 carbons long → Butane.
- Double Bond Position: The double bond is between C-2 and C-3.
- Substituents: There are two methyl groups (CH₃) on C-2.
- Name: 2,2-Dimethylbut-2-ene.

#### 2. Second Compound:
```
H3C
|
H3C-CH=CH-C-CH3
|
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 5 carbons long → Pentane.
- Double Bond Position: The double bond is between C-3 and C-4.
- Substituents: There are two methyl groups (CH₃) on C-3.
- Name: 3,3-Dimethylpent-3-ene.

#### 3. Third Compound:
```
CH3
/
H3C-CH-CH=C=CH2
\
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 5 carbons long → Pentane.
- Double Bond Position: The double bond is between C-4 and C-5.
- Substituents: There are two methyl groups (CH₃) on C-3.
- Name: 3,3-Dimethylpent-4-ene.

#### 4. Fourth Compound:
```
H2C=CH-C-CH3
|
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 4 carbons long → Butane.
- Double Bond Position: The double bond is between C-1 and C-2.
- Substituents: There are two methyl groups (CH₃) on C-2.
- Name: 2,2-Dimethylbut-1-ene.

#### 5. Fifth Compound:
```
H2C=CH-CH(C(CH3)3)-CH3
```
- Parent Chain: The longest chain containing the double bond is 4 carbons long → Butane.
- Double Bond Position: The double bond is between C-1 and C-2.
- Substituents: There is a tert-butyl group (C(CH₃)₃) on C-3.
- Name: 3-Tert-butylbut-1-ene.

#### 6. Sixth Compound:
```
H3C-CH2-CH=C-CH2-CH3
\
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 6 carbons long → Hexane.
- Double Bond Position: The double bond is between C-4 and C-5.
- Substituents: There are two methyl groups (CH₃) on C-3.
- Name: 3,3-Dimethylhex-4-ene.

#### 7. Seventh Compound:
```
H3C-CH2-CH=C-CH2-CH3
\
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 6 carbons long → Hexane.
- Double Bond Position: The double bond is between C-4 and C-5.
- Substituents: There are two methyl groups (CH₃) on C-3.
- Name: 3,3-Dimethylhex-4-ene.

#### 8. Eighth Compound:
```
H3C-CH2-CH=C-CH2-CH3
\
CH3
CH3
```
- Parent Chain: The longest chain containing the double bond is 6 carbons long → Hexane.
- Double Bond Position: The double bond is between C-4 and C-5.
- Substituents: There are two methyl groups (CH₃) on C-3.
- Name: 3,3-Dimethylhex-4-ene.

---

Final Answer:

\[
\boxed{
\begin{array}{l}
1. \text{2,2-Dimethylbut-2-ene} \\
2. \text{3,3-Dimethylpent-3-ene} \\
3. \text{3,3-Dimethylpent-4-ene} \\
4. \text{2,2-Dimethylbut-1-ene} \\
5. \text{3-Tert-butylbut-1-ene} \\
6. \text{3,3-Dimethylhex-4-ene} \\
7. \text{3,3-Dimethylhex-4-ene} \\
8. \text{3,3-Dimethylhex-4-ene}
\end{array}
}
\]