# Which Perfume Will You Smell First and Why?

## Explanation:

**Graham's Law of diffusion** states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. In this case, Perfume A has a molar mass of 275 g/mol while Perfume B has a molar mass of 205 g/mol. Using the formula based on Graham's Law:

Rate of diffusion (B) / Rate of diffusion (A) = square root of (Molar mass A / Molar mass B)

Substituting the molar masses of Perfume A and Perfume B into the formula, we get:

Rate of diffusion (B) / Rate of diffusion (A) = square root of (275/205) â 1.15

Therefore, Perfume B will diffuse 1.15 times faster than Perfume A. As a result, the person will smell Perfume B first due to its faster rate of diffusion.

So, in conclusion, when two perfumes are released at the same time and a person is standing 7.5 meters away, Perfume B with a lower molar mass will be detected first by the person based on Graham's Law of diffusion.