Aim : To prove that effect of acid in the stomach.
Apparatus and Chemicals : Leaves, vaseline, petroleum jelly, weak acid.
Procedure : Let us take two similar green leaves from school garden. Apply petroleum jelly on one leaf and leave the other freely. Add 1 or 2 drops of weak acid on both the leaves. Let us observe for sometime.
Observation : We find that the leaf applied with petroleum jelly has no change whereas, the leaf that has not applied with jelly is partly affected.
Result :
This shows that the function of petroleum jelly can be compared to that of mucus lining in the stomach walls.
Mucus is secreted by some cells present in the walls of the stomach. It forms a thin lining on the walls of the stomach.
This counteracts the action of acid.
Hence, the stomach is protected from damage caused by the secretion of its own acid.
