Chemistry
Assertion (A): Aluminium is obtained from its oxide by electrolysis (Hall-Heroult process).
Reason (R): Aluminium is generally not found in the form of aluminium oxide.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
A is true but R is false.
Explanation — Since aluminium is very reactive, it exists in nature as stable oxide (Al2O3). To extract aluminium from this stable compound, simple heating or chemical reduction is not sufficient. Therefore, electrolysis of molten alumina is used in the Hall–Héroult process. Hence, assertion (A) is true.
Aluminium is actually most commonly found in nature in the form of aluminium oxide (Al2O3), primarily within its main ore, Bauxite. Hence, reason (R) is false.
Related Questions
Assertion (A): Bayer's process is used in the extraction of aluminium from its main ore.
Reason (R): Bayer's process is done for the refinement of aluminium.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Reactive metals like calcium, magnesium cannot be obtained by reduction.
Reason (R): Reactive metals have a great affinity towards oxygen
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): For electrical heating devices like electric iron and heater, alloys are used.
Reason (R): Alloys have a greater resistance and low melting point.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Bronze is used in making medals, statues, etc.
Reason (R): Bronze is hard and easily cast.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.