Give structure formula of pent-3-en-2-ol.

Explanation

To derive the structure formula of pent-3-en-2-ol, we will follow these steps:

### Step 1: Identify the Carbon Chain
The name "pent" indicates that there are 5 carbon atoms in the longest chain.

**Hint:** The prefix "pent" refers to a 5-carbon chain.

### Step 2: Draw the Carbon Backbone
We will draw a straight chain of 5 carbon atoms:

```
C1 - C2 - C3 - C4 - C5
```

**Hint:** Each "C" represents a carbon atom in the chain.

### Step 3: Identify the Position of the Double Bond
The "3-ene" part of the name indicates that there is a double bond starting at the 3rd carbon atom. We will place a double bond between C3 and C4.

```
C1 - C2 - C3 = C4 - C5
```

**Hint:** The number before "ene" tells you where to place the double bond.

### Step 4: Identify the Hydroxy Group
The "2-ol" part of the name indicates that there is a hydroxyl (-OH) group attached to the 2nd carbon atom. We will add the -OH group to C2.

```
C1 - C2(OH) - C3 = C4 - C5
```

**Hint:** The number before "ol" indicates the position of the -OH group.

### Step 5: Add Hydrogen Atoms
Now, we need to add hydrogen atoms to each carbon to satisfy the tetravalency of carbon (each carbon must make four bonds):

- C1: 3 H (CH3)
- C2: 1 H + 1 OH (CH)
- C3: 1 H (C)
- C4: 1 H (C)
- C5: 3 H (CH3)

Putting it all together, we have the complete structure:

```
H H OH H H
| | | | |
H--C1--C2--C3=C4--C5--H
| | | | |
H H H H H
```

### Final Structure Formula
The structure formula of pent-3-en-2-ol can be represented as:

```
CH3
|
CH
|
CH
||
CH
|
CH3
```

Or in a more condensed form:

**C5H10O** or **CH3-CH(OH)-CH=CH-CH3**

### Summary
The structure formula of pent-3-en-2-ol is:

```
CH3
|
CH
|
CH
||
CH
|
CH3
```