How many geometrical isomers are possible for Hepta-2, 5-dienoic acid:

Answer

To determine the number of geometrical isomers for Hepta-2,5-dienoic acid, we can follow these steps:

### Step 1: Understand the Structure of Hepta-2,5-dienoic Acid
Hepta-2,5-dienoic acid has the following structure:
- It has a total of 7 carbon atoms (hence "hepta").
- There are double bonds between carbon atoms at positions 2 and 3, and at positions 5 and 6.

### Step 2: Identify the Double Bonds
In Hepta-2,5-dienoic acid, there are two double bonds:
- C2=C3
- C5=C6

### Step 3: Determine Conditions for Geometrical Isomerism
Geometrical isomerism (cis-trans isomerism) occurs due to restricted rotation around double bonds. For a compound to exhibit geometrical isomerism:
- Each carbon involved in the double bond must have different substituents.

### Step 4: Analyze Each Double Bond
1. **For the first double bond (C2=C3)**:
- C2 has two substituents: one is a hydrogen (H) and the other is part of the carbon chain.
- C3 also has two substituents: one is a hydrogen (H) and the other is part of the carbon chain.
- Since both carbons have different substituents, this double bond can exhibit cis and trans isomerism.

2. **For the second double bond (C5=C6)**:
- C5 has two substituents: one is a hydrogen (H) and the other is part of the carbon chain.
- C6 also has two substituents: one is a hydrogen (H) and the other is part of the carbon chain.
- Similarly, this double bond can also exhibit cis and trans isomerism.

### Step 5: Count the Total Geometrical Isomers
- Each double bond can exist in two forms (cis and trans).
- Therefore, for the two double bonds, the total number of geometrical isomers can be calculated as:
- For C2=C3: 2 isomers (cis and trans)
- For C5=C6: 2 isomers (cis and trans)

Thus, the total number of geometrical isomers = 2 (from C2=C3) × 2 (from C5=C6) = 4.

### Final Answer
The total number of geometrical isomers possible for Hepta-2,5-dienoic acid is **4**.

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