thanks dr Bob

got through 6 now I am stuck again

1. Hydrochloric acid + Sodium hydroxide > sodium chloride + water

2. Magnesium hydroxide + hydrochloric acid > Magnesium chloride + water

HCl + NaOH ==> NaCl + H2O

Already balanced.

Mg(OH)2 + HCl ==> MgCl2 + H2O
balanced is
Mg(OH)2 + 2HCl ==> MgCl2 + 2H2O.