Which ion produces a green precipitate with aqueous sodium hydroxide that then dissolves in excess aqueous sodium hydroxide?
- A$\text{Ca}^{2+}$
- B$\text{Cr}^{3+}$
- C$\text{Cu}^{2+}$
- D$\text{Fe}^{2+}$
Chemistry 0620 · IGCSE · Identification of ions and gases