Question

which of two diffuse slower: bromine vapour in air, or  copper sulphate  into water

Answer 1

Diffusion of copper sulphate into water is at slower rate compared to diffusion of bromine vapour into air.

Reason:
Rate of Diffusion is higher in gases than in solids.
So here CUSO4 crystals are solids which diffuse in water ( liquid) which is very very slow compared to bromine vapour which is gas.

Answer 2

Answer: the diffusion of copper sulphate in water is slow

Explanation: this is because diffusion occurs at faster rate in gases also show the copper sulphate is a solid and so it will take longer time to diffuse in a liquid where has bromine can diffuse very easily in the air because air is a gas this is the reason why copper sulphate in water diffusion will take place at a slower rate