Fe2(SO4)3 + Rb2SO4 + 24H2O → 2{RbFe(SO4)2•12H2O}
Iron(III) sulfate react with rubidium sulfate and water to produce dodekahydrate iron(III-rubidium sulfate. Iron(III) sulfate and rubidium sulfate - concentrated solutions. This reaction takes place at a temperature near 0°C.