Do transition metals form a white compound which dissolve into a colourless solution?

Answer 1

It depends what you are mixing with what, the question is too open to different variables to be answered. Transtional metals do not spontaneously change into white compounds without first reacting with something else. Only a few transtional metals form colourless solutions when a ligand has been attached i.e. linear molecules such as silver because they have a co ordination number of two. Different transtional metals form different colours in different oxidation states when dissolved therefore the question being asked makes no sense and cannot be answered.

Answer 2

Yes, some transition metals can form white compounds that dissolve into colorless solutions. For example, manganese(II) sulfate is a white solid that dissolves in water to form a colorless solution. These compounds typically involve transition metals in low oxidation states.