Molecular sieves are synthetic zeolite molecular sieve 3A is type A zeolite. Molecular sieves are hydrated metal alumino-silicates crystalline. Molecular sieve 3A has an actual pore size of 30. The molecular sieve’s adsorption capacity will depend on the pore size and pore volume of the molecular sieve. It is potassium-based alumino-silicates. It works on the principle of adsorption. It is also known as the potassium form of type A.