Which is the true regarding rate of formation of haloforms?

Options

A. Rate of formation of `"CHF"_(3)` is highest
B. Rate of formation of `"CHI"_(3)` is highest
C. Rate of formation of all are equal
D. Rates cannot be related

Answer

To determine which statement is true regarding the rate of formation of haloforms, we need to analyze the haloform reaction and its mechanism. Here’s a step-by-step solution:

### Step 1: Understand the Haloform Reaction
The haloform reaction involves the halogenation of methyl ketones in the presence of a base. The general reaction can be represented as follows:

\[ RCOCH_3 + 3X_2 \xrightarrow{\text{Base}} RCOO^- + CHX_3 \]

Where \( R \) is an alkyl group, \( X \) is a halogen (like Cl, Br, or I), and \( CHX_3 \) is the haloform product (like chloroform, bromoform, or iodoform).

**Hint:** The haloform reaction specifically involves methyl ketones and results in the formation of haloforms through halogenation.

### Step 2: Identify the Rate-Determining Step
The rate of the haloform reaction primarily depends on the formation of the enolate ion from the methyl ketone. The enolate formation is the slowest step in the reaction mechanism, which determines the overall rate of the reaction.

**Hint:** Focus on the enolate formation as it is crucial for the rate of the reaction.

### Step 3: Analyze the Role of Halogen Concentration
The rate of formation of haloforms is independent of the concentration of the halogen used. This means that regardless of whether you use Cl2, Br2, or I2, the rate of formation of haloforms remains the same as long as the methyl ketone and base are present.

**Hint:** Consider how the concentration of halogen affects the reaction rate.

### Step 4: Evaluate the Options
Given the above understanding, we can evaluate the options provided:
1. Rate of formation of CHF3 is higher than others.
2. Rate of formation of Iodoform is higher than others.
3. Rate of formation of all haloforms is equal.
4. Rate of formation of Bromoform is higher than others.

From our analysis, the third option is correct: the rate of formation of all haloforms is equal.

**Hint:** Compare the options with your understanding of the reaction's rate dependency.

### Conclusion
The true statement regarding the rate of formation of haloforms is that the rate of formation of all haloforms is equal, as it is independent of the concentration of halogen.