Question

What happens when Concentrated ${\mathrm{H}}_2{\mathrm{SO}}_4$is added to Sugar?

Answer 1

1. Sulphuric acid act as a dehydrating agent when added to sugar.
2. Here, Sulphuric acid does not react with sugar, in fact, it dehydrates the sugar molecule by removing the Hydrogen and Oxygen atom to form a water molecule (in the form of steam) as the water gets vapourised due to a lot of heat released in the reaction.
3. Since the reaction is a highly exothermic reaction a black mass of Carbon is left behind.
4. The reaction is shown below.

$$\begin{gathered} {\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}\left(\mathrm{s}\right)\stackrel{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }12\mathrm{C}\left(\mathrm{s}\right)+11{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right) \\ \mathrm{Cane}\mathrm{sugar}\mathrm{Carbon}\mathrm{Steam} \end{gathered}$$