Which of the following complex coordination compounds represents the highly water-soluble intermedia — Metallurgy and Isolation of Elements Chemistry Question

💡 Solution & Explanation

In Baeyer's process, the amphoteric Aluminium oxide in Bauxite reacts with concentrated $NaOH$ at high pressure to form a soluble coordination complex: $Al_2O_3 \cdot 2H_2O + 2NaOH + H_2O \rightarrow 2Na[Al(OH)_4]_{(aq)}$. This complex is also frequently written in its simplified dehydrated form as Sodium meta-aluminate, $NaAlO_2$.