Why is a liquid (the hydraulic fluid) used to operate the brakes in a car?

Bromine and air take about 15 minutes to diffuse completely but bromine diffuses into a vacuum very rapidly. Why is this so?

Bromine particles are almost twice as heavy as chlorine particles. Which gas will diffuse faster; bromine(vapour) or chorine? Explain your answer.

Explain why, a small volume of water in a kettle can fill a kitchen with steam.

Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into

(i) osmosis, and (ii) diffusion:

(a) swelling up of a raisin on keeping in water

(b) spreading of virus on sneezing

(c) earthworm dying on coming in contact with common salt

(d) shrinking of grapes kept in thick sugar syrup

(e) preserving of pickles in salt

(f) spreading of smell of cake being baked in the kitchen

(g) aquatic animals using oxygen dissolved in water during respiration