A polysaccharide 'X' on boiling with dil `H_2SO_4` at 393 K under 2-3 atm pressure yields ‘Y'.
'Y' on treatment with bromine water gives gluconic acid. 'X' contains B-glycosidic linkages Question only. Compound 'X' is :

Options

A. starch
B. cellulose
C. amylose
D. amylopectin

Answer

To solve the problem, we need to identify the polysaccharide 'X' based on the information provided. Let's break down the steps:

### Step-by-Step Solution:

1. **Understanding the Polysaccharide 'X':**
- The problem states that 'X' is a polysaccharide that contains β-glycosidic linkages.
- Common polysaccharides with β-glycosidic linkages include cellulose and some forms of starch.

2. **Reaction with Dilute H₂SO₄:**
- The polysaccharide 'X' is boiled with dilute H₂SO₄ at 393 K under 2-3 atm pressure.
- This treatment typically hydrolyzes polysaccharides into their constituent monosaccharides or oligosaccharides.

3. **Formation of 'Y':**
- The product 'Y' obtained from the hydrolysis of 'X' is then treated with bromine water, yielding gluconic acid.
- Gluconic acid is derived from glucose, indicating that 'Y' is likely a glucose derivative or a related sugar.

4. **Identifying 'X':**
- Since 'X' has β-glycosidic linkages and can yield glucose upon hydrolysis, we can deduce that 'X' is likely cellulose.
- Cellulose consists of β-D-glucose units linked by β-1,4-glycosidic bonds.

5. **Final Conclusion:**
- Therefore, the polysaccharide 'X' is cellulose.

### Final Answer:
The compound 'X' is **cellulose**.