(a)i) How would an aqueous solution of iron (II) tetraoxosulphate (VI) be converted into an aqueous solution of magnesium tetraoxosulphate (VI)?

(ii) Write a balanced equation for the reaction in (a)(i) above

 

(b)(i) Why are some compounds recrystallized after preparation?

(ii) Outline the steps in recrystallization

 

(C)(i) Name two gases that can cause color changes in an acidified solution of potassium heptaoxodichromate (VI)

(ii) State the color change expected in (c)i) above