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Acid and Base Salt Equation

Posted: Sat Jan 19, 2019 2:01 pm
by Nathaniel 2E
A problem calls for writing out the equilibrium equation for AlCl3. The solution writes it out as:

Al(H2O)6 3+ (aq) + H2O (l) <---> H3O+ (aq) + Al(H2O)5OH 2+ (aq)

What does the H2O in parentheses attached to the aluminum ions mean? Why do we assume they exist and write the equation like that?

Re: Acid and Base Salt Equation

Posted: Sat Jan 19, 2019 6:10 pm
by Alyssa Wilson 2A
This is a double replacement reaction, and we assume the aluminum ion is attached to a H2O molecule, because it is formed with a ligand complex that forms when AlCl3 reaches equilibrium. Al(H2O)5 OH2 is Pentaaqua-hydroxyaluminum(iii) ion.