Can i easily change these products back to the original reactants?

Question

- heating a copper wire in the blue flame that when the black substance is scraped off, the copper wire will be reddish copper again.

- combining sodium hydroxide solution and copper sulfate solution.

- combining silver nitrate solution and sodium chloride solution.

-combining zinc granules and diluted sulfuric acid with copper sulfate as a catalyst.

- burning of magnesium ribbon in a blue flame.

PLEASE TELL ME IF WHAT CHANGES DOES THEY EXHIBIT. this is important for our lab report. thanks.

PLEASE ANSWER IT ALL.

Answer 1

These are all one-way reactions, and not easily reversed.

1. black coating

2. blue precipitate

3. zinc dissolves, with fizzing (hydrogen)

4. bright white light, and a white powder left behind.