Textbook Problem 6D.15

[Joey_Okumura_1E]

Calculate the pH of 0.055 M AlCl3(aq)

For this, I believe AlCl3 splits into Al^(3+) and 3Cl-. I can ignore the Cl- since it is a weak base. Therefore, I have Al^(3+) which is a weak acid since it can attract OH.
1. Why doesn't Al^(3+) attract 3OH- molecules and therefore make the equation Ka = 3x^(2)/(0.055-x)?
2. Do I need to look up the Ka value on the internet? (I do not see it on the tables given in 6C)

[Sreeram Kurada 3H]

So for this problem you had to look at a table to see what alc3 would form. Al is kinda weird along with other metals in that it forms a polyatomic acid, so you would have to be given that information if on the test. The table you should look at is table 6d.1.