Question

Experiment to show break down of food by using the model of chalk piece kept in vinegar

Answer 1

PROCEDURE:

Set one piece of chalk aside on the table.Using either lemon juice or vinegar, fill a glass half full with the liquid. Place the chalk in the glass. The chalk does not have to be completely covered in the liquid.Set the glass aside for a couple of days.The chalk should begin dissolving and then be completely dissolved in a few days.You can try this chalk science experiment in school or at home using both vinegar and lemon juice.Put a piece of chalk (or half of a piece) into a glass of vinegar.Put the other half of the chalk (or a full piece) in a glass of lemon juice.The chalk will dissolve same as the food dissolve in our digestive system(gastric acid)

NOTE:Chalk is calcium carbonate while both vinegar and lemon juice are acidy.The vinegar or lemon juice acidity dissolves the chalk.

Answer 2

Concept:

Chalk piece contains Calcium Carbonate and Vinegar contains Acetic acid, a  weak acid.

When a Chalk piece is kept in a glass vessel containing Vinegar, it can be observed that the chalk piece dissolves in the solution.

Reaction that occurs behind this process is as follows:

Acetic acid + Calcium carbonate --> Water + Carbon dioxide + Calcium Acetate.

Experiment:

1. Crushed chalk piece powder is added to the vessel A containing vinegar.

2. A complete chalk piece is placed inside the vessel B containing vinegar.

Observation:

After sometime, it can be noted that Chalk piece powder dissolves faster than a full chalk piece.

This shows that in the process of digestion of food, crushing is necessary mechanically to make the breakdown of materials fast.