Used Commercial Refrigerators Questions About Chemistry?

Questions about chemistry? - used commercial refrigerators

1. The contents of the storage battery acid
Acetic
Hydrochloric
Nitric
Sulfuric
_______
2.Hydrogen sulfide forms a white precipitate when a solution
Cd (NO3) 2
Pb (NO3) 2
CuCl2
ZnSO4
______

3.A sulfur compound which is easily soluble sulfur
H2SO4
SO2
CS2
H2S
_____

4. When sulfur reacts with oxygen, heat
not released or absorbed
absorbed
Published
Sometimes free, sometimes absorbed
______

5.Sulfur carbon dioxide used in commercial refrigeration, as the gas
is easy to liquefy
dissolves in water
cold

_____
6.Si volume of sulfuric acid in a closed container increased gradually over a period of several weeks, the increase is probably due to the absorption
Carbon dioxide
Nitrogen
Oxygen
Water
_____
If you can answer, even if it would be useful. Moreover, if the number 3 is a reaction that would also be helpful. Thank you again.