What happens to chalk in lemon juice?

Chalk is composed primarily of calcium carbonate (CaCO3), while lemon juice contains citric acid (C6H8O7). When chalk is added to lemon juice, a chemical reaction takes place between the calcium carbonate and the citric acid. This reaction produces calcium citrate, water, and carbon dioxide gas.

The chemical equation for this reaction is:

CaCO3 + 2C6H8O7 → Ca(C6H5O7)2 + H2O + CO2

The calcium citrate is insoluble in water, so it forms a precipitate that settles at the bottom of the container. The water and carbon dioxide gas are released into the air.

The reaction between chalk and lemon juice can also be used to demonstrate the concept of acid-base reactions. In this reaction, the lemon juice acts as an acid, and the chalk acts as a base. The products of the reaction are a salt (calcium citrate) and water.