Carbonates are example of salts that are insoluble in water except those of potassium, sodium and ammonium. Chlorides on the other hand are salts which are soluble in water except silver chloride and lead ii chloride soluble in warm water. The reaction between calcium carbonate and potassium carbonate occurs as shown;
CaCo3 (s) + 2KCl (aq) = CaCl2 (aq) + K2CO3 (aq)
where s -solid state
aq- aqueous state
