1. Writing H(OH) (aq) as a product of the reaction of an acid and base. Hopefully, you realized that this product is H2O(l)
  2. Wriitng the incorrect molecular formula for a product. For example aluminum nitrate was often written as AlNO3, not correctly as Al(NO3)3. To write this correctly, you need to know that NO3 has a negative one charge, and from the formula for the reactants (as in reaction 5 - in this case Al(OH)3), you should surmise that Al ion has a charge of 3+.
  3. Not writing the simplest formula for a product. Fox example, sodium nitrate is not Na2(NO3)2, but rather NaNO3.
  4. Leaving off the (aq), (s), (l), or (g) after the product. How can you or I tell if you have a precipitation reaction if one of the products doesn't have an (s) after it?
  5. Not balancing the equations.
  6. Not recognizing that if you have a strong acid in the reactants and another reactant with OH, that the reaction is an acid/base reaction
  7. Automatically assuming that if you have a strong acid in the reactants that the reaction has to be an acid/base reaction. This is only true if you have a base like OH in the reactants.
  8. Assuming a reaction is a redox reaction without determining the oxidation number for each atom. (Obviously this is not necessary when the reaction is a combustion reaction using molecular oxygen, O2.
  9. Not knowing the charge on ions.
  10. Not putting () around certain ions when needed. For example iron hydroxide is Fe(OH)3 not FeOH3.