[copper2sulfate]

hi i am studying for a test tomorrow and just reviewing some notes and am really stuck!! pls *delete me*!
What type of reactions do the following reactions show. like double displacement, singledisplacement, synthesis, decomposition, neutralisation, combustion, corrosion. or even a combination. the followin are really confusing me.(equations not balanced)

1. H2S + SO2 = S + H2O (is this double disp. or even single disp+decomp?)

2. Sb2S3 + HCl = H3SbCl6 + H2S (looks kinda like some double disp. and synth?help?)

3. CuFeS2 + O2 = Cu + FeO + SO2 (what on earth???help pls??)

4. ZnS + O2 = ZnO + SO2 (corrosion?)

pls help me what are these?

[Jorriss]

Before anyone answers, do you have any ideas on what the answers may be?