Question

Impure bauxite on reaction with $NaOH$ gives __________
\[
  A.{\text{ }}Al{\left( {OH} \right)_3} \\
  B.{\text{ }}NaAl{O_2} \\
  C.{\text{ }}A{l_2}{O_3} \\
  D.{\text{ All the above}} \\
 \]

Answer 1

Hint- In order to deal with this question first we will talk about Bayer’s process, then we will discuss its condition further we will elaborate the term bauxite and after it we will write required reactions that are involved when the impure bauxite reacts with sodium hydroxide.

Complete step-by-step answer:
The Bayer process is the primary industrial means of bauxite processing for alumina (aluminum oxide) production. Bauxite, the most common aluminum ore, contains just $30\% - 60\% $ aluminum oxide \[A{l_2}{O_3}\] , the remainder being a combination of silica, various iron oxides, and titanium dioxide. Until being polished to an aluminum sheet, the aluminum oxide must be filtered.
The extraction process converts the aluminium oxide in the ore to soluble sodium aluminate, \[2NaAl{O_2}\], according to the chemical equation:
\[A{l_2}{O_3} + 2NaOH \to 2NaAl{O_2} + {H_2}O\]
Hence, impure bauxite on reaction with $NaOH$ gives \[NaAl{O_2}\]
So, the correct answer is option B.

Additional information- Ore is a natural rock or deposit containing one or more valuable minerals, usually metals, which can be extracted, refined and sold at a profit. Ore is mined from the soil by digging, and processed or refined to remove the precious metals or minerals, often by smelting. Ores are those minerals which conveniently and profitably extract metal from. There are primarily four types of ores such as Oxides; Ores carbonate; Sulphide; Ores halides.

Note- Bauxite is a rock formed from a reddish clay substance called laterite soil, which is found most frequently in tropical or subtropical areas. Bauxite consists mainly of aluminum oxide (alumina), silica, iron oxides, and titanium dioxide compounds. This is flexible and malleable in aluminium. Aluminum is used in a wide range of items from canisters, foils, cooking utensils, window frames, and beer kegs and aircraft components.