Q1: Aluminium is extracted from

ANS:B - bauxite

Bauxite is a sedimentary rock composed primarily of aluminum hydroxide minerals, along with various impurities such as iron oxides, silica, and other minerals. It is the primary ore from which aluminium is extracted. Here are some key characteristics and aspects of bauxite:

1. Composition: Bauxite primarily consists of aluminum hydroxide minerals, including gibbsite [Al(OH)3], boehmite [AlO(OH)], and diaspore [α-AlO(OH)]. These minerals are collectively known as the aluminum ore minerals. However, bauxite may also contain varying amounts of impurities, such as iron oxides (hematite and goethite), silica (quartz), titanium dioxide, and other minerals.
2. Formation: Bauxite forms through the weathering and chemical alteration of aluminum-rich rocks and minerals in tropical and subtropical regions with high rainfall. The weathering process involves the leaching of soluble components, leaving behind residual aluminum hydroxides that accumulate as bauxite deposits.
3. Appearance: Bauxite typically has a dull, earthy appearance and varies in color from reddish-brown to yellowish-brown, depending on the mineral composition and impurities present.
4. Occurrence: Bauxite deposits are found in various parts of the world, particularly in tropical and subtropical regions with suitable climatic and geological conditions. Major bauxite-producing countries include Australia, Guinea, Brazil, Jamaica, and China.
5. Extraction: The process of extracting aluminium from bauxite involves refining the ore to obtain alumina (aluminium oxide) through a chemical process known as the Bayer process. In this process, bauxite ore is crushed and digested in a caustic soda (sodium hydroxide) solution at elevated temperatures, which dissolves the aluminium hydroxides while leaving behind the impurities. The resulting alumina is then purified further and processed through electrolysis to produce pure aluminium metal.