Draw the cis and trans structures of hex-2-ene. Which isomer will have higher b.p. and why?

Explanation

To solve the problem of drawing the cis and trans structures of hex-2-ene and determining which isomer has a higher boiling point, we can follow these steps:

### Step 1: Understand the structure of hex-2-ene
Hex-2-ene is an alkene with six carbon atoms and a double bond between the second and third carbon atoms. The general formula for alkenes is CnH2n, so for hex-2-ene (C6H12), we can visualize the structure.

### Step 2: Draw the carbon skeleton
1. Start with a straight chain of six carbon atoms:
```
C1 - C2 - C3 - C4 - C5 - C6
```

### Step 3: Add the double bond
2. Place a double bond between the second and third carbon atoms:
```
C1 - C2 = C3 - C4 - C5 - C6
```

### Step 4: Add hydrogen atoms
3. Add hydrogen atoms to satisfy the tetravalency of carbon. The structure will look like this:
- C1: CH3
- C2: CH (with one hydrogen and one alkyl group)
- C3: CH (with one hydrogen and one alkyl group)
- C4: CH2
- C5: CH2
- C6: CH3

So the complete structure is:
```
CH3 - CH = CH - CH2 - CH2 - CH3
```

### Step 5: Draw the cis isomer
4. For the cis isomer, the two substituents (hydrogens) on the double bond will be on the same side:
```
H H
\ /
C = C
/ \
CH3 CH2-CH2-CH3
```

### Step 6: Draw the trans isomer
5. For the trans isomer, the two substituents (hydrogens) on the double bond will be on opposite sides:
```
H CH3
\ /
C = C
/ \
CH3 H
```

### Step 7: Compare boiling points
6. To determine which isomer has a higher boiling point, we need to consider the polarity of the molecules:
- The cis isomer has a higher dipole moment due to the arrangement of the substituents, leading to stronger intermolecular dipole-dipole interactions.
- The trans isomer has a lower dipole moment because the dipoles cancel each other out.

### Conclusion
7. Therefore, the cis isomer of hex-2-ene will have a higher boiling point than the trans isomer due to its greater polarity and stronger intermolecular forces.

### Summary of the Solution:
- The cis structure has both hydrogen atoms on the same side of the double bond, while the trans structure has them on opposite sides.
- The cis isomer has a higher boiling point due to stronger dipole-dipole interactions resulting from its polar nature.