Benzaldehyde is

Options

A. less reactive in electrophillic addition reactions than propanal
B. More reactive in nucleophillic addittion reactions than propanal
C. less reactive in nucleophillic addittion reactions than propanal
D. equally reactive in nucleophillic addittion reaction than propanal.

Answer

To determine the nature of benzaldehyde and compare its reactivity with propanal, we can follow these steps:

### Step 1: Identify the Structure of Benzaldehyde and Propanal
- **Benzaldehyde** has the structure: \( C_6H_5CHO \) (where the carbonyl group is attached to a benzene ring).
- **Propanal** has the structure: \( CH_3CH_2CHO \) (a straight-chain aldehyde).

### Step 2: Understand the Reaction Type
Both benzaldehyde and propanal contain a carbonyl group (C=O), which is polar due to the difference in electronegativity between carbon and oxygen. This polarity makes the carbon atom of the carbonyl group electrophilic, allowing it to undergo nucleophilic addition reactions.

### Step 3: Explain Nucleophilic Addition Reaction
In a nucleophilic addition reaction:
- A nucleophile (electron-rich species) attacks the electrophilic carbon of the carbonyl group.
- The double bond between carbon and oxygen breaks, leading to the formation of a tetrahedral intermediate.
- The oxygen atom then typically becomes negatively charged (alkoxide ion), and a proton (H⁺) is added to stabilize the product.

### Step 4: Compare Reactivity of Benzaldehyde and Propanal
- **Inductive Effect**: The benzene ring in benzaldehyde exerts a +I (positive inductive) effect due to its electron-donating nature. This stabilizes the positive charge on the carbonyl carbon, making it less electrophilic.
- In contrast, propanal does not have such a stabilizing effect from a large aromatic ring. Therefore, the carbonyl carbon in propanal is more electrophilic and more susceptible to nucleophilic attack.

### Step 5: Conclusion
Based on the above analysis, we can conclude that:
- **Benzaldehyde is less reactive in nucleophilic addition reactions compared to propanal**. The presence of the benzene ring stabilizes the carbonyl carbon, making it less electrophilic.

### Final Answer
Benzaldehyde is less reactive in nucleophilic addition reactions than propanal.

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