Chloroform is prepared by the use of bleaching powder. The organic compound taken is 
`A) C_2H_5OH " " B) CH_3CHO`
`C) C Cl_3CHO " " D) CH_3COOH`

Options

A. A,B,C
B. B,C,D
C. A,C,D
D. A,B,D

Answer

To determine which organic compound can be used to prepare chloroform using bleaching powder, we need to analyze the reactions involved in the process.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
Chloroform (CHCl3) can be prepared from bleaching powder (calcium oxychloride, Ca(OCl)2) through a series of reactions. The first step involves the release of chlorine gas when bleaching powder is mixed with water:
\[ \text{Ca(OCl)}_2 + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{Cl}_2 \]

2. **Oxidation of Ethyl Alcohol**:
The chlorine gas produced acts as an oxidizing agent. If we consider ethyl alcohol (C2H5OH), it can be oxidized to acetaldehyde (CH3CHO):
\[ \text{C}_2\text{H}_5\text{OH} + \text{Cl}_2 \rightarrow \text{CH}_3\text{CHO} + \text{HCl} \]

3. **Formation of Trichloroacetyldehyde**:
The acetaldehyde can further react with more chlorine to form trichloroacetyldehyde (CCl3CHO):
\[ \text{CH}_3\text{CHO} + 3\text{Cl}_2 \rightarrow \text{CCl}_3\text{CHO} + 3\text{HCl} \]

4. **Final Reaction to Form Chloroform**:
Finally, trichloroacetyldehyde reacts with calcium hydroxide to produce chloroform and calcium formate:
\[ \text{CCl}_3\text{CHO} + \text{Ca(OH)}_2 \rightarrow \text{CHCl}_3 + \text{HCOO}\text{Ca} \]

5. **Identifying the Correct Option**:
Now, we need to evaluate the given options:
- A) C2H5OH (Ethyl alcohol) - Can be oxidized to acetaldehyde and further to chloroform.
- B) CH3CHO (Acetaldehyde) - Can directly react with chlorine to form trichloroacetyldehyde.
- C) CCl3CHO (Trichloroacetyldehyde) - Can react with calcium hydroxide to form chloroform.
- D) CH3COOH (Acetic acid) - Does not participate in the formation of chloroform through this method.

Therefore, options A, B, and C can be used to prepare chloroform.

### Conclusion:
The correct organic compounds that can be taken for the preparation of chloroform from bleaching powder are **A) C2H5OH, B) CH3CHO, and C) CCl3CHO**.