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6D.11 E

Posted: Mon Dec 02, 2019 11:31 am
by ayushibanerjee06
For 6D.11 E, why does AlCl3 affect the pH by making it more acidic? I got 2AlCl3 + 3H20 -> Al2O3 + 6HCl

Re: 6D.11 E

Posted: Mon Dec 02, 2019 11:37 am
by Brian Tangsombatvisit 1C
To show a chemical reaction of an acid reacting with water, the acid should donate one of its protons to water to form hydronium. However, since AlCl3 doesn't have any protons, it must first be hydrated with water. This makes sense since Al is a transition metal, and transition metals react with water to form complex ions - in this case, Al likes to form an octahedral complex with 6 water molecules. Now that Al is hydrated, it can donate a proton to water to form hydronium, expressing the qualities of an acid and lowering pH of the solution.