Which is not correct in case of boric acid ?

Options

A. It is a tribasic acid
B. It has planar structure
C. It acts as monobasic acid
D. It is soluble in hot water

Answer

To determine which statement about boric acid is not correct, we will analyze the properties of boric acid step by step.

### Step 1: Identify the properties of boric acid.
Boric acid (H₃BO₃) is known for several key properties:
- It is often referred to as a weak acid.
- It has a trigonal planar structure.
- It is soluble in hot water.
- It can donate one proton (H⁺) in a reaction.

### Step 2: Evaluate the statements given in the question.
1. **It is a tri-basic acid.**
2. **It has a planar structure.**
3. **It acts as a monobasic acid.**
4. **It is soluble in hot water.**

### Step 3: Analyze each statement.
- **Statement 1:** "It is a tri-basic acid."
- This statement is **not correct**. Boric acid is classified as a monobasic acid because it can donate only one proton (H⁺) in aqueous solution.

- **Statement 2:** "It has a planar structure."
- This statement is **correct**. Boric acid has a trigonal planar structure around the boron atom.

- **Statement 3:** "It acts as a monobasic acid."
- This statement is **correct**. Boric acid behaves as a monobasic acid because it can donate one H⁺ ion.

- **Statement 4:** "It is soluble in hot water."
- This statement is **correct**. Boric acid is indeed soluble in hot water.

### Step 4: Conclusion
The statement that is not correct regarding boric acid is that it is a tri-basic acid. Therefore, the correct answer is that boric acid is a monobasic acid.

### Final Answer
The statement that is not correct in case of boric acid is: **It is a tri-basic acid.**

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