Question

How many moles of fructose and galactose respectively are obtained on hydrolysis of 1 mole stachyose?

• A. 1, 1
• B. 2, 2
• C. 3, 1
• D. 1, 2

Hint:

Stachyose hydrolysis yields 1 mole of fructose and 2 moles of galactose. This reaction is an example of polysaccharide breakdown.

Answer 1

The Correct Option is D

Step 1: Understanding the structure of stachyose.
Stachyose is a tetrasaccharide made up of two galactose units, one glucose unit, and one fructose unit. On hydrolysis, it breaks down into these monosaccharides.
Step 2: Analyzing the options.
(A) 1, 1: This is incorrect, as hydrolysis yields more galactose.
(B) 2, 2: This is incorrect, as there is 1 mole of fructose and 2 moles of galactose.
(C) 3, 1: This is incorrect as it doesn't match the correct stoichiometry.
(D) 1, 2: This is correct because hydrolysis of 1 mole of stachyose yields 1 mole of fructose and 2 moles of galactose.
Step 3: Conclusion.
The correct answer is (D) 1, 2.