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Net Ionic Equations and Balancing

I'm not sure what it is about this stuff that confuses me but I can't seem to get this stuff to stick. Detailed work would be kindly appreciated.

Write balanced molecular, ionic and net ionic equations for the following:
1. Mg(OH)2 (aq) + HCL (aq) --> MgCl2 (aq) + H20 (l)
2. K2(C2O4) (aq) + CaCl2 (aq) --> KCL (aq) CA(C2O4) (s)
3. (NH4)3PO4 (aq) + Zn(NO3)2 (aq) --> NH4NO3 (?) + Zn3(PO4)2 (?)
4. LiOH (aq) + VCl3 (aq) --> LiCl (?) --> V(OH)3 (?)
5. Na2CO3 (aq) + HCL (aq) --> NaCl (?) + CO2 (?) + H20 (?)
6. Mg(NO3)2 (aq) + NaCrO4 (aq) --> NaNO3 (?) + MgCrO4 (?)
7. FeCl3 (aq) + Mg (s) --> MgCl2 (aq) + Fe (s)
8. BaBr2 (aq) + Na2SO4 (aq) --> ?????

These are only eight out of a fifty-three question hand out, but with eight answers to reference off of I think I'll be far more successful in my attempts at this.

Solution Preview

Let's first define what ionic equations and net ionic equations are. I suggest you take a look at this website before reading the rest:

http://www.files.chem.vt.edu/RVGS/ACT/notes/Notes_on_Net_ionic_rxns.html

So ionic equations basically split off the molecules into their ionic components, if applicable. The first molecule in question one for example:
Mg(OH2)
Mg2+ + 2OH-

As a result, the ionic equation (unbalanced) of question 1 would be:

Mg2+ + 2OH- + H+ + Cl- ---> Mg2+ + 2Cl- + H2O (l)

Notice water, being a stable product that remains a liquid as denoted by the equation you're given, will be considered as a whole and not an ion in these ionic equations. The same goes for solid products (refer to example in link above).

If you look carefully at the above, the equation is not balanced. We have just one chloride ion (Cl-) on the left, but clearly have two on the right. This means that we need different proportions of the reactants. It's easier to consider the chemical equation of this reaction for balancing purposes (not so many +/-'s that get in the way):

Mg(OH)2 (aq) + HCL (aq) --> MgCl2 (aq) + H20 (l)

Mg(OH)2 (aq) + 2HCL (aq) --> MgCl2 (aq) + 2H20 (l)

Notice I've balanced all the elements in the equation: 1 x Mg, 2 x O, 4 x H, 2 x Cl.
Let's expand this to a balanced, ionic equation:

Mg2+ (aq) + 2OH- (aq) + 2H+ (aq) ...

Solution Summary

The expert examines net ionic equations and balancing equations.

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