Chemistry help?

Question

I need help with these chemical reactions. If you can tell the tyep of reaction, predict the products, and write a balanced equation

1. Ammonium sulfate reacts with barium nitrate
2. Zinc metal is added to a solution of copper (II) chloride
3. Propane gas (C3H8) is burned in excess oxygen
4. Dinitrogen pentoxide gas is added to distilled water

Answer 1

I'll tell you products, you can figure out the balances; they are not that difficult (comment on #3)
1. You will have to check solubilities. All cations and anions would be in solution unless one pair
(BaSO4)?? precipitates out.
2. Zn will reduce the copper to elemental form
Cu(0), while it is oxidized to Zn(II). The net effect is to swap zinc for copper in solution.
3. CO2 and H2O are formed. For each molecule of propane that is burned, 3 CO2 and 4H2O are formed by mass balance. So from the products, you need 10 g-atoms of oxygen. Since oxygen comes as a dimer in normal form, you need 5O2 in the equation.
4. N2O5 or O2N-O-NO2 forms HNO3 when dissolved in water. From the structure above you can figure out how much H2O is needed to convert the gas to the acid.