When sucrose is broken down, it forms two simpler sugars: glucose and fructose. This process is called hydrolysis, which means breaking down a molecule using water.

Here's the chemical equation for the reaction:

Sucrose + Water → Glucose + Fructose

The role of acid in this reaction is as a catalyst. Catalysts speed up chemical reactions without being consumed in the process. In the case of sucrose hydrolysis, the acid (usually a weak acid like citric acid or hydrochloric acid) provides hydrogen ions (H+) that help to break the bond between glucose and fructose in the sucrose molecule.

Here's how it works:

1. Protonation: The acid donates a proton (H+) to the sucrose molecule, making it more susceptible to attack by water.

2. Nucleophilic attack: A water molecule attacks the carbon atom bonded to the oxygen atom that was protonated.

3. Bond breaking: The bond between glucose and fructose is broken, and two separate molecules are formed: glucose and fructose.

Without the acid, the hydrolysis of sucrose would occur at a much slower rate. This is because the bond between glucose and fructose is relatively strong and requires a significant amount of energy to break. The acid provides the necessary energy for the reaction to proceed at a reasonable pace.