" Positive charge colloid is "

Match the items given in Column I and Column II. {:(,"Column I","Column II"),(A.,"Protective colloid",1.FeCl_(3)+NaOH),(B.,"Liquid-liquid colloid",2."Lyophilic colloids"),(C.,"Positively charged colloid",3."Emulsion"),(D.,"Negatively charged colloid",4.FeCl_(3)+"hot water"):}

Match the items given in Column I and Column II. {:(,"Column I","Column II"),(A.,"Protective colloid",1.FeCl_(3)+NaOH),(B.,"Liquid-liquid colloid",2."Lyophilic colloids"),(C.,"Positively charged colloid",3."Emulsion"),(D.,"Negatively charged colloid",4.FeCl_(3)+"hot water"):}

SnO_(2) forms positively charged colloidal sol in acidic medium and negatively charged colloidal sol in basic medium. Explain ?

What is the average size of colloidal particles? Name two negatively charged and two positively charged colloids.

SnO_2 forms a positively charged colloidal solution in acidic medium and a negetively charged colloidal solution in basic medium. Explain.