Question

The chief impurity present in red bauxite is ______
A. $Si{{O}_{2}}$
B. $F{{e}_{2}}{{O}_{3}}$
C. ${{K}_{2}}S{{O}_{4}}$
D. $NaF$

Answer 1

An ore is a mixture of minerals, metals, and impurities that occur naturally and from which metal or minerals can be extracted economically. And Hematite is the most preferred source of iron in India Now to calculate the purity in $5kg$ of $F{{e}_{2}}{{O}_{3}}$ first try to know the amount of Fe present in $F{{e}_{2}}{{O}_{3}}$

Complete step by step answer:
In the given question, we have to tell the name the impurities which are found in the red bauxite ore.
The impurities found in the bauxite ore are iron oxide, silica, titania, etc. The percentage of alumina in bauxite is $35\text{ }to\text{ }65$the percentage of silica, is $0.5\text{ }to\text{ }10$and the percentage of iron oxide is 2 to 30%. - When the concentration of iron oxide is large in the ore, then it is considered as red bauxite whereas if the concentration of silica is large the ore is considered as the white bauxite. Therefore, iron oxide and silica are the two impurities of the bauxite ore.
The extraction of the bauxite can be done by the process such as Bayer's process and HallHeroult's process. In Bayer's process, the production of aluminium oxide takes place after which in Hall- Heroult's process it pure aluminium is extracted by the smelting method. It is widely used in the electric industry, airplane making industry, etc.
Therefore, the correct answer is option B.

Note: While calculating the mass percentage remember to calculate only the mass percentage of the required metal. For example, Hematite ore is used for the extraction of Iron metal, hence we have only, calculated the percentage amount of $Fe$ present in $F{{e}_{2}}{{O}_{3}}$ the three oxygen atoms can be reduced to give the required metal.