This is question 6D.15 part b. The question asks to find the pH of 0.055M of AlCl3. The molecules is polar covalent so my initial thought was pH = 7. However, if the molecule were to break up, Al3+ would bond with water to create Al(OH)3. But first, I can't find the ka value for Al3+ in the textbook (but I did find it online to be 1.4*10^-5) and also when I balance the equation out:
2Al3+ + 6H20 <--> 2Al(OH)3 + 6H+,
I get:
(6x)^6*(2x)^2/0.055^2 = 1.4* 10 ^-5
x = 0.114436
pH = 0.94
Which is wrong. The answer is pH.= 3.25
pH of AlCl3
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Aditya Desai 1A
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