Question

Metal cations can act as lewis acids in water to produce an acidic solution even though the metal ion contains no hydrogen. Water hydrates the ions in solution and partial loss of electrons from water allows hydrogen ion to be lost

What is the pH of a 0.1209M solution of Al3+ ions, if it has a Ka of 1.400*10-5?

Answer 1

Al(H2O)6(3+)==>Al(H2O)5(OH^-)(2+) + H^+
Write the Ka expression, set up an ICE chart, substitute into the Ka expression and solve for H^+, then convert to pH.