Consider the following statements about glucose.
(A) When sucrose is boiled with dilute HCl in alcoholic solution, glucose and fructose are obtained in equal amounts.
(B) Commercially, glucose is obtained by hydrolysis of starch by boiling it with dilute H2SO4 at 393 K under pressure.
(C) Glucose is a ketohexose and is also known as dextrose.
(D) Glucose is the monomer of many of the larger carbohydrates, such as starch and cellulose.
Which of the statements given above are correct? Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (B) and (D) only
Glucose is made by the acid hydrolysis of a larger carbohydrate: cane sugar (sucrose) in the laboratory, and starch on a commercial scale.
(A) When sucrose is boiled with dilute HCl in alcoholic solution, glucose and fructose are obtained in equal amounts. — True. One molecule of sucrose takes up one molecule of water and gives one glucose and one fructose:
\( \displaystyle \ce{C12H22O11 + H2O} \xrightarrow{\ce{H+}} \ce{C6H12O6 + C6H12O6} \)
(sucrose → glucose + fructose)
(B) Commercially, glucose is obtained by hydrolysis of starch by boiling it with dilute H2SO4 at 393 K under pressure. — True. Starch is a polymer of glucose, so its hydrolysis gives glucose only:
\( \displaystyle \ce{(C6H10O5)_{n} + nH2O} \xrightarrow[\text{393 K; 2-3 atm}]{\ce{H+}} \ce{nC6H12O6} \)
(C) Glucose is a ketohexose and is also known as dextrose. — False. Glucose has an aldehyde group and six carbon atoms, so it is an aldohexose.
Its other name, dextrose, is correct.
(D) Glucose is the monomer of many of the larger carbohydrates, such as starch and cellulose. — True. Starch and cellulose are both built from glucose units, which is why their hydrolysis gives glucose.
NCERT (2026-27 edition):
10.1.2.1 Glucose – “1. From sucrose (Cane sugar): If sucrose is boiled with dilute HCl or H2SO4 in alcoholic solution, glucose and fructose are obtained in equal amounts.”
“2. From starch: Commercially glucose is obtained by hydrolysis of starch by boiling it with dilute H2SO4 at 393 K under pressure.”
“Glucose is an aldohexose and is also known as dextrose. It is the monomer of many of the larger carbohydrates, namely starch, cellulose.”