For many medical conditions, glucose has been administered in patients for a long time…

For many medical conditions, glucose has been administered in patients for a long time. Diseases like hypoglycemia, hyperkalemia, etc. are treated by administering glucose in patients. Thus, it was necessary to manufacture glucose in larger quantities. This gave rise to the discovery of laboratory methods of preparation of glucose. Some of which are-
From sucrose: Boiling sucrose with dilute hydrochloric acid or sulphuric acid in an alcoholic solution leads to the formation of glucose and fructose. The reaction is-
\(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}+\mathrm{H}_{2} \mathrm{O} \xrightarrow{\mathrm{H}^{+}} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\)
Sucrose is also called cane sugar.
From starch: When starch is hydrolyzed by boiling it with dilute sulphuric acid at 393 K under pressure, it leads to the formation of glucose. This technique is mostly used for the commercial preparation of glucose.
\(\underset{\text { Starnh ac cellubse }}{\left(\mathrm{C}_{6} \mathrm{H}_{10} \mathrm{O}_{5}\right)+\mathrm{H}_{2} \mathrm{O}} \xrightarrow[393 \mathrm{~K} \cdot 2-3 \mathrm{amm}]{\mathrm{H}^{+}} n \underset{\text { Chirose }}{\longrightarrow} \mathrm{C}_{6} \mathrm{H}_{10} \mathrm{O}_{6}\)
The preparation of glucose from sucrose and starch requires which of the following substances?