Need help on chemistry really bad! I don't understand how to do it!?

to write balanced equations you have to make sure that the same number of each element appears on both sides of the arrow. All of the reactions you have listed are double replacement reactions, which means that the first element in each compound are going to switch places. After that you need to make sure the charges are equal (so the compound has an overall charge of 0) hope that helps a little.. and sorry but i don't know what the unit would be..i just got done with those questions in school and we never had to put lables/units on them.