Too add to what tav said about number 2, you need to remember to write the charges for each ion on both sides of the equation. Remember any ion or atom that keeps the same charge is a spectator ion. For example the chlorine in ZnCl would be written as [Cl]<sup>-1</sup>

Also to get superscript type out &lt;sup&gt;Text here&lt;/sup&gt;
For subscript type out &lt;sub&gt;Text here&lt;/sub&gt;