Write increasing order of basic strength of following:
`(a)CH_(3) - CH_(2) - overset(..)NH_(2)" "(b)CH_(3)- CH = overset(..)NH`
`(c)CH_(3) - C -=overset(..)N`

Answer

To determine the increasing order of basic strength of the given amines, we need to analyze the hybridization of the nitrogen atom in each compound and how it affects the availability of the lone pair of electrons for protonation.

Let's analyze each compound step by step:

1. **Identify the compounds:**
- (a) CH₃-CH₂-NH₂ (Ethylamine)
- (b) CH₃-CH=NH (Vinylamine)
- (c) CH₃-C≡N (Propyne)

2. **Determine the hybridization of nitrogen in each compound:**
- In (a) CH₃-CH₂-NH₂, the nitrogen is sp³ hybridized. This means it has a lone pair of electrons that is more available for bonding because it has 25% s character and 75% p character.
- In (b) CH₃-CH=NH, the nitrogen is sp² hybridized. Here, the lone pair has 33% s character and 67% p character, which makes it less available for bonding compared to sp³.
- In (c) CH₃-C≡N, the nitrogen is sp hybridized. This means it has 50% s character and 50% p character, making the lone pair even less available for bonding.

3. **Compare the basic strengths based on hybridization:**
- The basic strength decreases as the s character increases because the lone pair becomes less available for protonation.
- Therefore, the order of basic strength based on hybridization is:
- CH₃-CH₂-NH₂ (sp³) > CH₃-CH=NH (sp²) > CH₃-C≡N (sp)

4. **Write the increasing order of basic strength:**
- The increasing order of basic strength is:
- CH₃-C≡N < CH₃-CH=NH < CH₃-CH₂-NH₂

**Final Answer:**
Increasing order of basic strength:
CH₃-C≡N < CH₃-CH=NH < CH₃-CH₂-NH₂

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