The ionic compound of Fe3+ and SO4 2- would be Fe2(SO4)3 or Iron (III) sulfate. <span>It is a rhombic crystalline salt and soluble in water at room temperature. It is used in dyeing as a </span>mordant<span>, and as a coagulant for industrial wastes.</span>
Liquids take the shape of their container.
Like pouring water into a cup would make the water settle into the shape of the cup.
POH will be -log[conc of OH]
-log (3.9E-08) = 7.409
pH = 14- pOH
pH = 14 - 7.409
pH = 6.59