Question

Why diffusion takes place faster when two gases are brought in contact with each other?

Answer 1

Diffusion is basically this process where molecules merge together due to their kinetic energy of their random motion(Brownian motion). In gases, the intermolecular forces are extremely weak. So, when the molecules of the other gas come in contact with the previous gas, the molecules of the other gas tend to accumulate the spaces between the molecules of the previous gas and mix up easily allowing diffusion to take place.