Do you expect different products in solution when aluminium (III) chloride and potassium chloride treated separately with (i) normal water (ii) acidified water, and (iii) alkaline water? Write equations wherever necessary.

Potassium chloride is the salt of strong acid [HCl] and strong base [KOH] and hence it is neutral in nature and thus when dissolved in water it dissociate to give potassium and chloride ions. The reaction is given as below:

KCl K+ + Cl-


In acidified and alkaline water, the ions do not react and remain as such.


Aluminium chloride is formed due to the reaction of a strong acid [HCl] with a weak base [Al (OH)3]. Hence, it undergoes hydrolysis in normal water.


AlCl3 + 3H2O Al (OH)3 + 3H+ + 3Cl-


In acidified water, H+ ions react with Al (OH)3 forming water and giving Al3+ ions. Hence, in acidified water, AlCl3 will exist as Al3+ and Cl-ions.



In alkaline water, the following reaction takes place:



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