Give answers to the following question:
During the extraction of aluminium, bauxite is first converted into alumina by Baeyer’s process. This involves treating bauxite with a chemical and then processing the resulting compounds to obtain pure alumina.
i. In Baeyer’s process, bauxite is treated with which chemical to form a soluble compound?
ii. After treating bauxite with NaOH and precipitating aluminium hydroxide, which product is obtained upon ignition at 1000°C?