What mass of Cu2+ ion is produced by the reaction of 0.50 g of Cu metal?

What mass of Cu²⁺ ion is produced by the reaction of 0.50 g of Cu metal?

Cu atom loses 2 electrons to give Cu²⁺. The mass of the 2 electrons is negligible when comparing with the mass of Cu atom or Cu²⁺ ion.
Hence, mass of Cu²⁺ produced = 0.50 g


====
What volume of 6.0 M NaOH is required to completely percipitate the mass of Cu²⁺ ion?

Molar mass of Cu²⁺ = Molar mass of Cu = 63.5 g/mol

Cu²⁺(aq) + 2OH⁻(aq) → Cu(OH)₂(s)
OR: Mole ratio Cu²⁺ : OH⁻ = 1 : 2

No. of moles of Cu²⁺ reacted = (5.0 g) / (63.5 g/mol) = 5.0/63.5 mol
No. of moles of OH⁻ needed = (5.0/63.5 mol) × 2 = 10/63.5 mol

1 mole of NaOH contains 1 mole of OH⁻.
No. of moles of NaOH needed = 10/63.5 mol
Volume of 6.0 M NaOH needed = (10/63.5 mol) / (6.0 mol/L) = 0.026 L = 26 mL