Boric acid is used in carrom boards for smooth gliding of pawns because

Options

A. `H_(3)BO_(3)` molecules ar loosely chemically bonded and hence soft.
B. Its low density makes its fluffy.
C. It si chemically inert with plywood.
D. H-bonding in `H_(3)BO_(3)` give it a layered structure.

Answer

### Step-by-Step Solution:

1. **Understanding Boric Acid**: Boric acid (H₃BO₃) is a compound that consists of boron, oxygen, and hydrogen. It is commonly used in various applications, including as a lubricant in carom boards.

2. **Properties of Boric Acid**: The structure of boric acid features hydrogen and hydroxyl (OH) groups that are bonded loosely. This loose bonding contributes to its unique properties.

3. **Lubricating Action**: The soft nature of boric acid allows it to act as a solid lubricant. When applied to the surface of a carom board, it reduces friction between the pawns and the board, allowing for smoother gliding motion.

4. **Analyzing the Options**:
- **Option 1**: "H₃BO₃ molecules are loosely chemically bonded and hence soft." - This statement is correct as the loose bonding contributes to its lubricating properties.
- **Option 2**: "Its low density makes it fluffy." - This statement is incorrect as the fluffiness does not relate to its use as a lubricant.
- **Option 3**: "It is chemically inert with plywood." - This statement is also incorrect as it does not explain the lubricating properties.
- **Option 4**: "Hydrogen bonding in H₃BO₃ gives it a layered structure." - This statement is incorrect as it does not relate to the lubrication function.

5. **Conclusion**: The correct reason for the use of boric acid in carom boards for smooth gliding of pawns is that the H₃BO₃ molecules are loosely chemically bonded, making it soft and effective as a lubricant.

### Final Answer:
Boric acid is used in carom boards for smooth gliding of pawns because H₃BO₃ molecules are loosely chemically bonded and hence soft, acting as a solid lubricant that reduces friction.

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