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(A): Pyrolusite is an ore of manganese. ...

(A): Pyrolusite is an ore of manganese.
(R) : Formula of pyrolusite is `Mn_(3)O_(4)`.

A

Both A & R are true, R is the correct explanation of A

B

Both A & R are true, R is not correct explanation of A

C

A is true, R is false

D

A is false, R is true

Text Solution

Verified by Experts

The correct Answer is:
C
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AAKASH SERIES-D - BLOCK ELEMENTS-OBJECTIVE EXERCISE - 1 (ASSERTION AND REASON TYPE)
  1. (A): Fe^(+3) is more stable than that of Fe^(+2). (R) : Fe^(+3) ion ...

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  2. (A): Sc^(+3) ion in aqueous solutions is colorless (R) : Ions with d...

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  3. (A): Cu^(+) is diamagnetic (R): Ions with dl configuration are diama...

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  4. (A): Transition elements form alloys easily (R) : Transition element...

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  5. (A): Transition elements form alloys very easily. (R): They exhibit ...

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  6. (A): Elements of second and third transition series have nearly same a...

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  7. (A) : Transition metals form colored ions (R): They have completely ...

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  8. (A): Magnetic moment of Mn^(+2) is 5.8 B.M (R): Mn^(+2) has five unp...

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  9. (A) : Cu^(+2)(aq) is more stable than Cu^(+)(aq) (R): Heat of hydrat...

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  10. (A): Zn(II) compounds are diamagnetic. (R): Zn(II) has all its elect...

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  11. (A): FeO is basic in character. (R): Oxides of transition metals are...

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  12. (A): Pyrolusite is an ore of manganese. (R) : Formula of pyrolusite ...

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  13. (A): Equivalent mass of K(2)Cr(2)O(7), when it acts as oxidizing agent...

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  14. (A): Ti(IV) in aqueous solutions is colour less. (R): Ti(IV) has no ...

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  15. (A): In alkaline medium, KMnO(4) oxidizes iodides to iodates. (R): K...

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  16. (A): Zr and Hf have nearly equal atomic radii. (R): Zr and Hf belong...

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  17. (A) : The most common oxidation state of lanthanides is +3. (R): Lan...

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  18. (A): Ce^(4+) is a good oxidizing agent. (R): Sm^(2+) is a good reduc...

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  19. (A): Zinc does not show characteristic properties of transition metals...

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  20. (A): K(2)CrO(4) has yellow colour due to charge transfer (R) : CrO(4...

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