In each of the following pair of compounds, which is more basic in aqueous solution? Give an explanation for your choice:
`n-PrNH_(2)" or "CH_(3)CN`

Answer

To determine which of the two compounds, n-PrNH₂ (n-propyl amine) or CH₃CN (acetonitrile), is more basic in aqueous solution, we need to analyze the basicity of each compound based on the availability of the lone pair of electrons on the nitrogen atom.

### Step-by-Step Solution:

1. **Identify the Compounds:**
- n-PrNH₂ (n-propyl amine) has the structure: CH₃-CH₂-CH₂-NH₂.
- CH₃CN (acetonitrile) has the structure: CH₃-C≡N.

2. **Determine the Hybridization of Nitrogen:**
- In n-PrNH₂, the nitrogen atom is sp³ hybridized. This means it has a lone pair of electrons that is more available for donation.
- In CH₃CN, the nitrogen is part of a triple bond (C≡N) and is sp hybridized. The sp hybridization has 50% s-character, which makes the lone pair of electrons more tightly held and less available for donation.

3. **Analyze the Basicity:**
- Basicity is related to the availability of the lone pair of electrons for protonation. The more available the lone pair, the stronger the base.
- The sp³ hybridized nitrogen in n-PrNH₂ has a lower s-character (25%) compared to the sp hybridized nitrogen in CH₃CN (50%). Therefore, the lone pair on the nitrogen in n-PrNH₂ is more available for donation.

4. **Conclusion:**
- Since n-PrNH₂ has a more available lone pair due to its sp³ hybridization, it is more basic than CH₃CN in aqueous solution.

### Final Answer:
n-PrNH₂ (n-propyl amine) is more basic than CH₃CN (acetonitrile) in aqueous solution.

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