The standard reduction potential for Cu²⁺, the voltage measured between a standard hydrogen electrode and a Cu electrode immersed in a solution where [Cu²⁺] = 1.00 M, is 0.340 V. The positive voltage indicates that the following reaction is spontaneous. H₂(g) + Cu²⁺(aq) → 2H⁺(aq) + Cu(s)
What would be the Cu²⁺ reduction potential if the standard hydrogen electrode was kept the same, but copper electrode were instead immersed in a solution of 0.450 M NaOH that was saturated with Cu(OH)₂? (The Ksp of Cu(OH)₂ is 2.20 × 10⁻²⁰).

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)