5. Dehydration of [tex]$CH_3-CH_2-CH_2-CH_2-OH$[/tex] gives:

A. [tex]$CH_2=CH-CH_2-CH_3$[/tex]
B. [tex][tex]$CH_3CH=CH-CH_3$[/tex][/tex]
C. [tex]$H-C\equiv C-CH_2-CH_3$[/tex]
D. [tex]$CH_3-C\equiv C-CH_3$[/tex]

6. The general formula of alkanols is represented as:

A. [tex][tex]$C_nH_{3n+2}OH$[/tex][/tex]
B. [tex]$C_nH_{2n+1}OH$[/tex]
C. [tex]$C_nH_{4n-1}OH$[/tex]
D. [tex][tex]$C_nH_{2n+3}OH$[/tex][/tex]



Answer :

Sure, let's address each question step-by-step.

### Question 5
Dehydration of [tex]\( CH_3-CH_2-CH_2-CH_2-OH \)[/tex] gives:

1. Identify the given compound:
The given compound is [tex]\( CH_3-CH_2-CH_2-CH_2-OH \)[/tex], which is butanol (specifically 1-butanol).

2. Concept of dehydration:
Dehydration of an alcohol involves removing a molecule of water (H₂O). This generally leads to the formation of an alkene.

3. Structure of the starting molecule:
[tex]\( CH_3-CH_2-CH_2-CH_2-OH \)[/tex] can be rewritten to make visualization of possible products easier.

4. Mechanism of dehydration:
The hydroxyl group (-OH) and a hydrogen atom from an adjacent carbon atom are removed to form a double bond.

5. Identify the possible products based on the location of hydrogen:
There are two adjacent hydrogens: one on the carbon attached to -OH (alpha carbon) and one on the next carbon (beta carbon).

In this case:
- Removing H from the alpha carbon gives [tex]\( CH_2=CH-CH_2-CH_3 \)[/tex] (1-butene).
- Removing H from the beta carbon gives [tex]\( CH_3-CH=CH-CH_3 \)[/tex] (2-butene).

Given the context and the usual primary pathway for such dehydrations, the likely major product is [tex]\( CH_2=CH-CH_2-CH_3 \)[/tex] (1-butene).

Correct answer: A. [tex]\( CH_2=CH-CH_2-CH_3 \)[/tex]

---

### Question 6
The general formula of alkanols is represented as:

1. Understand alkanols:
Alkanols are alcohols derived from alkanes by replacing one hydrogen atom with a hydroxyl group (OH).

2. General formula for alcohols:
- Start with the general formula for alkanes: [tex]\( C_nH_{2n+2} \)[/tex].
- Replace one hydrogen atom with OH.

3. Derivation:
- Starting with [tex]\( C_nH_{2n+2} \)[/tex].
- Replacing one H with OH doesn't change the number of carbon atoms, but adjusts the number of H atoms:
[tex]\[ \text{Initial alkane: } C_nH_{2n+2} \][/tex]
[tex]\[ \text{Atom replaced: } H_{2n+2-1} + OH = H_{2n+1}OH \][/tex]

Correct answer: B. [tex]\( C_nH_{2n+1}OH \)[/tex]

---

To summarize:
5. The dehydration of [tex]\( CH_3-CH_2-CH_2-CH_2-OH \)[/tex] gives: A. [tex]\( CH_2=CH-CH_2-CH_3 \)[/tex]
6. The general formula of alkanols is represented as: B. [tex]\( C_nH_{2n+1}OH \)[/tex]