Can someone help on this problems chemistry problems:?

H(+) + I(-) ---> HI [Hydrogen has one positive(+) charge; iodine has one negative(-) charge.]

Li(+) + HCl ---> LiCl + H(+) [Single replacement: lithium is more reactive than hydrogen( lithium is below hydrogen on the PT) and it replaces itself with Cl.]

Na(sub 2)CO(sub 3) ---> Na(sub 2)O + CO(sub 2) [The minus 2 charge from carbonate crisscross with sodium. Na gives the electrons to oxygen.]

HgO ---> Hg(2+) + O(2-) [Both mercury(2+) and Oxygen(2-) have two charges, which cancel each other out.]

MgOH(sub 2) ---> MgO + H(sub 2)O [Mg and O both have two of opposite charges.]