|Latex coagulates when acid is added.|
Latex coagulates when ethanoic acid is added to it. Explain.
- Latex is a mixture of rubber particles and water. Rubber particle is made up of a protein membrane that surrounds many rubber molecules.
- The negatively charged protein membrane prevent repel each other. Latex does not coagulate.
- Acid which consists of H+ ion is added into the latex.
- The H+ ion from acids neutralize the negatively charged protein membrane.
- The rubber particles collide with each other.
- Protein membrane of the rubber particle breaks.
- Rubber molecules clump together. Latex coagulates.
When latex is exposed to the air for some time, it still coagulates. Why?
- Bacteria from the air enter the latex.
- The growth of bacteria produces lactic acid.
- Lactic acid causes coagulation of latex. But this process occurs slowly. Why?
- Slow bacteria action.
How to prevent coagulation of latex? Explain.
- By adding ammonia solution.
- Ammonia solution consists of OH- ion that neutralize the acid produced by the bacteria.
- The rubber particles remain negatively charged.
- Coagulation of latex is prevented.
|5H students are studying coagulation of latex by adding ethanoic acid|
|Ethanoic acid is added drop by drop into latex in the beaker. The latex is stirred by using glass rod.|