# Can hydrogen gas reduce copper(II) ion?

I have a solution of copper(II) sulfate, and I would love to precipitate the copper metal. From looking at the standard reduction potential table, it appears that I can do this by bubbling hydrogen gas through the solution. However, the potential is not very large, so I am unsure of how well this approach would work. I was also wondering if sodium metabisulfite could be used for this purpose. I know I can precipitate copper carbonate with sodium carbonate and reduce with carbon, but this will take more time, and probably result in a large loss of product. I would also like to avoid precipitating the metal with another metal, because I am demonstrating how metals can be isolated so it would be silly to use a metal that is even harder to reduce.

Use electrolysis, it is much easier and faster to set up, without high temperatures or poisonous gases ($\ce{SO4^2-}$ is very hard to oxidise). So copper will plate out on the cathode and oxygen gas will bubble out on the anode.