The constant motion and high velocities of gas particles lead to some important practical consquences. One such consquences is that gases mix rapidly when they come in contact. Take the stopper off a bottle of perfume, for instance, and the odour will spread rapidly through the room as perfume molecules mix with the molecules in the air. This mixing of different gases by random molecular motion and with frequent collision is called diffusion. A similar process in which gas molecules escape without collision through a tiny hole into a vacuum is called effusion. Both the processes follow Graham's law which is mathematically put as `r prop sqrt(1//d)`. The average distance travelled by molecules between successive collisions is called mean free path.
Answer the following questions on the basis of the above information:
Select the correct statement(s).

Options

A. All gases diffuse spontaneously into one another when they are brought into contact.
B. Diffusion into a vacuum will take place much more rapidly than diffusion into another gas
C. The rates of diffusion and effusion of a goes depend on its molar mass.
D. All of the above statements are correct.

Explanation

To solve the question regarding the statements about the diffusion and effusion of gases, we will analyze each statement based on the information provided.

### Step-by-Step Solution:

1. **Understanding Diffusion**:
- The first statement claims that "all gases diffuse spontaneously into one another when they are brought into contact."
- This is true as diffusion is the process where gas particles mix due to their constant motion and random collisions. Therefore, this statement is **correct**.

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