Which of the following is a correct statement ?

Options

A. `C Cl_(3)-CHO` gives aldol condensation.
B. When mixture of ethanal and propanal is treated with aqueous NaOH, the product contains four aldols.
C. Mixture of HCHO and `CH_(3)CHO` will not give aldol condensation.
D. HCHO is least reactive towards oxidation.

Answer

To determine which of the given statements is correct, we will analyze each option step by step.

### Step 1: Analyze Option 1
**Statement:** CH3CHO gives aldol condensation.

**Analysis:**
- Aldol condensation requires the presence of alpha hydrogen atoms adjacent to the carbonyl group.
- In CH3CHO (acetaldehyde), there is one alpha hydrogen atom (the hydrogen on the carbon adjacent to the carbonyl group).
- Therefore, CH3CHO can undergo aldol condensation.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Option 2
**Statement:** When a mixture of ethanol and propanol is treated with aqueous NaOH, the product contains 4 aldols.

**Analysis:**
- Ethanol (C2H5OH) and propanol (C3H7OH) can undergo aldol condensation when treated with a base like NaOH.
- The aldol condensation can produce multiple products due to the different combinations of the two alcohols.
- However, the exact number of aldol products formed needs to be verified through the reaction mechanism.

**Conclusion:** This statement is **correct**.

### Step 3: Analyze Option 3
**Statement:** Mixture of CHO and CH3CHO will not give aldol condensation.

**Analysis:**
- CHO (formaldehyde) does not have any alpha hydrogen, while CH3CHO (acetaldehyde) does.
- The presence of CH3CHO means that aldol condensation can occur since it has alpha hydrogen.
- Therefore, this statement is **incorrect**.

### Step 4: Analyze Option 4
**Statement:** CHO is least reactive towards oxidation.

**Analysis:**
- CHO (formaldehyde) is actually more reactive towards oxidation than other aldehydes due to its structure.
- Therefore, this statement is also **incorrect**.

### Conclusion
After analyzing all the options, the correct statement is:

**Correct Answer:** Option 1 (CH3CHO gives aldol condensation) and Option 2 (when a mixture of ethanol and propanol is treated with aqueous NaOH, the product contains 4 aldols) are both correct.