138. Задачка по химии №013 893

With a sufficiently slow introduction of the H2SO4 substance into a dilute solution of the CaCl2 substance, the formation of a hydrosol of the CaSO4 substance is possible. Write the formula of micelles and indicate the sign of the electric charge of the colloidal particles of this sol. Which of the recommended substances is the most economical coalescer for this sol? What other possibilities are there for separating the CaSO4 substance from the liquid?
Coagulator: ZnCl2, AlCl3, NaCH3COO.