Step 1: Understanding the Concept:
Starch is a polysaccharide made up of many glucose units linked by glycosidic bonds. Hydrolysis breaks these bonds.
Step 3: Detailed Explanation:
In industrial production, starch is boiled with dilute sulfuric acid (\(H_2SO_4\)) at \(393 \text{ K}\) under \(2-3 \text{ atm}\) pressure.
The glycosidic linkages are cleaved by water, yielding a large number of glucose molecules.
Reaction:
\[ (C_6H_{10}O_5)_n + nH_2O \xrightarrow[393 \text{ K, } 2-3 \text{ atm}]{H^+} nC_6H_{12}O_6 (\text{Glucose}) \]
Excess acid is neutralized with chalk (calcium carbonate), and the solution is concentrated to get glucose crystals.
Step 4: Final Answer:
Glucose is prepared commercially by the acid hydrolysis of starch.