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(A) Aluminium metal is used as a reducin...

(A) Aluminium metal is used as a reducing agent in thermite welding
(R) Al has a lower melting point than Fe, Cr and Mn.

A

Both (A) and (R) are true and (R) is the correct explanation of (A)

B

Both (A) and (R) are true and (R) is not the correct explanation of (A)

C

(A) is true but (R) is false

D

Both (A) and (R) are false

Text Solution

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The correct Answer is:
B
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AAKASH SERIES-PRINCIPLES OF METALLURGY-Objective exercise -4 (Assertion (A) & Reason (R) type questions :
  1. (A) In smelting, roasted ore is heated with powdered coke in presenc...

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  2. (A) Leaching is the process of converting the ore into oxide and the...

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  3. (A) Aluminium metal is used as a reducing agent in thermite welding ...

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  4. (A) Lead, tin and bismuth are purified by liquation method . (R) Lead...

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  5. (A) Pin oil is fused as a foaming agent in froth floatation process ...

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  6. (A) Aluminium metal can be extracted by the electrolysis of aqueous al...

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  7. (A) Magnesium can not be extracted by electrolysis of aqueous salt s...

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  8. (A) Iron metal is refined in blast furnace (R) Blast furnace is used...

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  9. (A) Van Arkel method is a vapour phase refining process (R) Vapours...

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  10. (A) For iron extraction usually Fe(2) O(3) is used but not FeS(2) ...

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  11. (A) In the case of an ore contaning ZnS and PbS, the one depresant lik...

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  12. (A) In Froth floatation proess collectors like pine oil is added (R)...

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  13. (A) During leaching of Al from bauxite seeding agent freshly prepare...

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  14. (A) The thermodynamical reaction proceeds forward if Delta G is negat...

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  15. (A) Mg metal is not used for reduction of Al(2) O(3) thermodynamically...

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  16. (A) The reduction of metal oxide is easier if the metal is in liquid s...

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  17. (A) At all conditions Mg can reduce Al(2) O(3) (R) Below 135^(@)C M...

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  18. (A) In metallurgy of Al , the electrolyte is bauxite mixed with cryoli...

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  19. (A) The reduction of leached copper ore will be advisable with Iron ...

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  20. (A) H(2) is good reducing agent but not widely used in metallurgical ...

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