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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
In which of the following compounds, the oxidation state of I-atom is highest -A. `KI_(3)`B. `KIO_(4)`C. `DIO_(3)`D. `IF_(5)` |
| Answer» Correct Answer - B | |
| 502. |
Cartain materials such as turpentine oil, unsaturated organic compound, phosophorus, metals such as `Zn`, and `Pb`, etc., can absorb `O_(2)` from air in the presence of `H_(2)O`, which is converted to absorb `O_(2)` from air in the presence of `H_(2)O`, which is converted to `H_(2)O_(2)`. This is called autoxidation. Intermolecular redox reactions are those in which one molecule is oxidised and the other is reduced. Intramolecular redox reactions are those in which oen atom of a molecule is oxidised and the other atom is reduced. Which of the following reactions is`//`are auto redox or induced oxidation reaction `(s)`A. `Pb+O_(2)+H_(2)OrarrPbO+H_(2)O_(2)`B. `Na_(2)SO_(3)+Na_(3)AsO_(3)+O_(2)rarrNa_(2)SO_(4)+Na_(3)AsO_(4)`C. `RCH=CHR+O_(2)+2H_(2)Orarr2RCH=O+2H_(2)O_(2)`D. |
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Answer» Correct Answer - A::B::C::D `(a), (b)`, and `(c )` are auto or induced redox reaction. `(d)` is a disproportionation reaction. |
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| 503. |
Cartain materials such as turpentine oil, unsaturated organic compound, phosophorus, metals such as `Zn`, and `Pb`, etc., can absorb `O_(2)` from air in the presence of `H_(2)O`, which is converted to absorb `O_(2)` from air in the presence of `H_(2)O`, which is converted to `H_(2)O_(2)`. This is called autoxidation. Intermolecular redox reactions are those in which one molecule is oxidised and the other is reduced. Intramolecular redox reactions are those in which oen atom of a molecule is oxidised and the other atom is reduced. Which of the following reactions is`//`are none of the reactions mentioned in the question?A. `Ag(NH_(3))^(o+)overset(2H^(o+))rarrAg^(o+)+NH_(4)^(o+)`B. `Cr_(2)O_(7)^(2-)+2overset(ө)OHrarr2CrO_(4)^(2-)+H_(2)O`C. `NH_(4)^(o+)rarrNH_(3)`D. `2NO_(2)rarrN_(2)O_(4)` |
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Answer» Correct Answer - A::B::C::D All are none reactions since in all the reactions the oxidation states of reactant and product do not change. |
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| 504. |
Oxidation number of `P` in `Ba(H_(2)PO_(2))_(2)` isA. `+2`B. `+3`C. `+1`D. `-1` |
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Answer» Correct Answer - C `H_(2)PO_(2)^(-1)=2+x-4= -1impliesx=+1` |
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| 505. |
The oxidation number of an atom in a given species (molecule, ion of free atom) is the :A. acutal charge of the atomB. valency of the atomC. formal charge of the atomD. actual charge of the atom is the atom exits as a monotomic ion, or the hypothetical charge assigned to the atom in the species by sipmple rules. |
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Answer» Correct Answer - d |
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| 506. |
The oxidation number of `S` in `S_(8),S_(2)F_(2)`, and `H_(2)S`, respectively, areA. `0`, `+1` and `-2`B. `+2`, `+1` and `-2`C. `0`, `+1` and `+2`D. `-2`, `+1` and `-2` |
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Answer» Correct Answer - A `overset(*)(S_(8))=0` `overset(*)(S_(2))F_(2)=+1` `H_(2)overset(*)(S)= -2` |
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| 507. |
Nitric oxide acts as a reducing agent in which of the following reaction ?A. `4NH_(3) + 5O_(2) rarr 2NO + 6H_(2)O`B. `2NO + 3l_(2) + 4 H_(2)O rarr 2NO_(3)^(-) + 6l^(-) + 8 H^(+)`C. `2NO + H_(2)SO_(3) rarr N_(2)SO_(4)`D. `2NO + H_(2)S rarr N_(2)O + S + H_(2)O` |
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Answer» Correct Answer - B `2 overset(+2)(N)O + 3l_(2) + 4H_(2)O rarr 2 overset(+5)(N)O_(3)^(-) + 6l^(-) + 8H^(+)` Hence, NO acts as a reducing agen t and reduces `l_(2)` to `l^(-)` since, the oxidation number of nitrogen changes from `+2` in `NO` to `+5` in `NO_(3)^(-)` |
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| 508. |
In which of the following, increasing orders the oxidation number of oxygen has been arranged ?A. `BaO_(2) lt KO_(2) lt O_(3) lt OF_(2)`B. `OF_(2) lt KO_(2) lt BaO_(2) lt O_(3)`C. `BaO_(2) lt O_(3) lt OF_(2) lt KO_(2)`D. `KO_(2) + OF_(2) lt O_(3) lt BaO_(2)` |
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Answer» Correct Answer - A `Ba overset(-1)O_(2) lt overset(-0.5)(O_(2)) lt overset(0)O_(3) lt overset(+2)OF_(2)`. |
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| 509. |
Nitric oxide acts as a reducing agent in which of the following reaction ?A. `4NH_(2) + 5O_(2) to 2NO + 6H_(2)O`B. `2NO + 3I_(2) + 4H_(2)O to 2NO_(3)^(-) + 6I^(-) + 8H^(+)`C. `2NO + H_(2)SO_(3) to N_(2)O + H_(2)SO_(4)`D. `2NO + H_(2)S to N_(2)O + S + H_(2)O` |
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Answer» Correct Answer - B `2 overset(+2) (NO) + 3I_(2) + 4H_(2)O to 2 overset(+5)(N)O_(3)^(-) + 6I^(-) + 8H^(+)` Hence, no acts as a reducing agent and reduces `I_(2)` to `I^(-)` since, the oxidation number of nitrogen changes from `+2` in `NO^(-)` to `+5` in `NO_(3)^(-)` |
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| 510. |
Which of the following is the example of a disproportionation reaction?A. `CaCO_(3) to CaO + CO_(2)`B. `2HCuCl_(2) to Cu + Cu^(2+) + 4Cl^(-) + 2H^(+)`C. `PCl_(5) to PCl_(3) + Cl_(2)`D. `2H_(2)S + SO_(2) to 3S + 2H_(2)O` |
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Answer» Correct Answer - B (a) `underset(+2)underset(uarr)(Ca) underset(+4)underset(uarr)(C)overset(-2)overset(darr)O_(3) to underset(+2)underset(uarr)(Cu) + underset(+2)underset(uarr)(Cu^(2+)) + underset(-1)underset(uarr)(4Cl^(-)) + underset(+1)underset(uarr)(2H^(+))` Thus, `Cu^(+)` disproportionates to Cu and `Cu^(2+)`. (c) P is reduced and Cl is oxidised. (d) `H_(2)S` is oxidised and `SO_(2)` is reduced. |
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| 511. |
An aqueous solution of `6.3 g` oxalic acid dihydrate is made up to `250 mL`. The volume of `0.1 N NaOH` required to completely neutralise `10 mL` of this solution isA. 40mLB. 20mLC. 10mLD. 4mL |
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Answer» Correct Answer - a |
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| 512. |
The oxidation number of oxygen in hydrogen peroxide isA. `+1`B. `-1`C. `+2`D. `-2` |
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Answer» Correct Answer - B In `H_(2)O_(2)` Let the ON of oxygen `= x` Then, `2 (+1) + 2(x) = 0` or `2 + 2x = 0` or `2x = -2` or `x = -1` |
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| 513. |
The oxidation number of `Cr` is `+6` in :A. `FeCr_(2)O_(4)`B. `Fe_(2)(CrO_(4))_(2)`C. `Cr_(2)(SO_(4))O_(3)`D. `[Cr(OH)_(4)]^(-)` |
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Answer» Correct Answer - b |
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| 514. |
In which of the following redox reactions are neither the reactants nor the products favored ?A. ` Co(s) +Ni^(2+) (aq.)rarr Co^(2+) (aq.) + Ni(s)`B. ` Cu(s) +2Ag^(2+) (aq.) rarr Cu^(2+) (aq.) +2 Ag(s)`C. `Zn(s) +Cu^(2+) (aq.) rarr Zn^(2+) (aq.) + Cu(s)`D. ` Fe(s) +3Cu^(2+) (aq.) rarr 2Fe^(3+) (aq.) + Cu(s)` |
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Answer» Correct Answer - A At equlubrium, chemical tests reveal that both `Ni^(2+)` (aq.) and `Co^(2+) (aq)` are pesent at moderate concentrations. |
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| 515. |
In basic medium, `I^(-)` is oxidised by `MnO_(4)^(-)` . In this process, `I^(-)` changes to :A. `IO_(3)^(-)`B. `I_(2)`C. `IO_(4)^(-)`D. `IO^(-)` |
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Answer» Correct Answer - a |
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| 516. |
Which of the following is not a redox reaction ?A. `CuO+H_(2)rarrCu+H_(2)O`B. `Na+H_(2)OrarrNaOH+1/2 H_(2)`C. `CaCO_(3)rarr CaO+CO_(2)`D. `2K+F_(2)rarr2KF` |
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Answer» Correct Answer - C `overset(+2)(Ca)overset(+4-2)(CO_(3))rarroverset(+2-2)(CaO)+overset(+4-2)(CO_(2))` Since there is no change in oxidation number of any species, it is not a redox reaction. |
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| 517. |
On the basis of standard electrode potential values, suggest which of the following reactions would take place? (Consult the book for `E^(ϴ)` value) (a) `Cu+Zn^(2+)toCu^(2+)+Zn` (b) `Mg+Fe^(2+)toMg^(2+)+Fe` (c ) `Br_(2)+2Cl^(-)toCl_(2)+2Br^(-)` (d) `Fe+Cd^(2)toCd+Fe^(2+)` |
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Answer» The following reactions would take place `(i) Mg+Fe^(2+)rarrMg^(2+)Fe` `(ii) Fe+Cd^(2+)rarrFe^(2+)+Cd` |
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| 518. |
Why does flluorine not shown disproportionation reaction? |
| Answer» Fluorine dows not show disproportionation reaction because its atom can oly lose an electron (-1 oxidation state) and cannot accept it | |
| 519. |
The oxidation number of `S` in `H_(2)S_(2)O_(8)` isA. `+2`B. `+4`C. `+6`D. `+7` |
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Answer» Correct Answer - C The chemical structure of `H_(2)S_(2)O_(8)` is as follows: `H-overset(O)overset(||)underset(O)underset(||)(O)-S-O-O-S-overset(O)overset(||)underset(O)underset(||)(O)-H` So the oxidation number of `S` should be: `underset((for H))(2xx(+1))+underset((for S))(2xx X)+underset((for OforO-O))(6xx(-2))=0` or `X=+6 |
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| 520. |
A compound contains atoms A, B and C. the oxidation number of A is `+2`, of B is `+5` and of C is `-2`. The possible formula of the compound isA. `XYZ_(2)`B. `Y_(2)(XZ_(3))_(2)`C. `X_(3)(YZ_(4))_(2)`D. `X_(3)(Y_(4)Z)_(2)` |
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Answer» Correct Answer - C Sum of the oxidation numbers of atoms in it, is zero. |
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| 521. |
A compound contains atoms A, B and C. the oxidation number of A is `+2`, of B is `+5` and of C is `-2`. The possible formula of the compound isA. `ABC_(3)`B. `B_(2)(AC_(3))_(2)`C. `A_(3)(BC_(4))_(2)`D. `A_(3)(BC_(3))_(2)` |
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Answer» Correct Answer - C The oxidation states of A, B and C are `+2, +5` and `-2` respectively In `ABC_(3), 2 + 5 + 3 xx (-2) = +1 != 0` (b) In `B_(2) (AC_(3))_(2), 2 xx (+2) + 2 [(+5) + 3 (-2)] = +2 != 0` (c) In `A_(3) (BC_(4))_(2), 3 xx (+2) + 2[(+5) + 4 (-2)] = 0` (d) In `A_(3) (BC_(3))_(2), 3 xx (+2) + 2 [(+5) + 3 (-2)] = +4 != 0` `:.` Possible formula of compound is `A_(3) (BC_(4))_(2)` |
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| 522. |
A compound contains atoms X, Y and Z. The oxidation number of X is `+3`, Y is `+5` and Z is `-2`. The possible formula of the compound isA. `XYZ_(2)`B. `Y_(2)(XZ_(3))_(2)`C. `X_(3)(YZ_(4))_(3)`D. `X_(3)(Y_(4)Z)_(2)` |
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Answer» Correct Answer - C Let formula is `X_(x),Y_(y),Z_(z)`. O.N of X, Y and Z are `+3, +5 and -2` respecitvely `:. 3x +5y - 2z=0`. The values of x,y and z satisfying this equation are 3,3 and 12 Therefore correct formula is `X_(3)(YZ_(4))_(3)`. |
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| 523. |
A compound contains three elements `A,B` and `C`, if the oxidation number of `A=+2B=+5` and `C=-2` then possible formula of the compound isA. `ABC_(2)`B. `A_(2)(BC_(3))_(2)`C. `A_(3)(BC_(4))_(2)`D. `A_(3)(B_(4)C)_(2)` |
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Answer» Correct Answer - c |
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| 524. |
A compound contains three elements `A,B` and `C`, if the oxidation number of `A=+2B=+5` and `C=-2` then possible formula of the compound isA. `ABC_(2)`B. `B_(2)(AC_(3))_(2)`C. `A_(3)(BC_(4))_(2)`D. `A_(3)(B_(4)C)_(2)` |
| Answer» Correct Answer - C | |
| 525. |
A compound contains X, Y and Z atoms. The oxidation state of X, Y and Z are `+2, +2` and `-2` respectively. The possible formula of the compound isA. `XYZ_(2)`B. `Y_(2) (XZ_(3))_(2)`C. `X_(3)(Y_(4)Z)_(2)`D. `X_(3)(YZ_(4))_(3)` |
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Answer» Correct Answer - A The oxidation number of X, Y and Z are `+2, +2` and `-2` respectively (a) In `XYZ_(2) = (+2) + (+2) + 2(-2) = 0` (b) In `Y_(2) (XZ_(3))_(2) = 2 (+2) + 2(+2) + 6(-2) != 0` (c) In `X_(3) (Y_(4)Z)_(2) = 3 (+2) + 8 (+2) + 2 (-2) != 0` (d) In `X_(3) (YZ_(4))_(3) = 3 (+2) + 3 (+2) + 12 (-2)!= 0` |
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| 526. |
A compound contains three elements `A,B` and `C`, if the oxidation number of `A=+2B=+5` and `C=-2` then possible formula of the compound isA. `A_(2)(BC_(3))_(2)`B. `A_(3)(BC_(4))_(2)`C. `A_(3)(B_(4)C)_(2)`D. `ABC_(2)` |
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Answer» Correct Answer - B Compound formed from A, B and C is that for which sum of oxidation number is zero. `underset(+6)underset(uarr)(A_(3)) underset(+10)underset(uarr)B underset(-16)underset(uarr)((C_(4))_(2)) " correct"` |
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| 527. |
The oxidant which cannot act as a reducing agent isA. `CO_(2)`B. `SO_(2)`C. `NO_(2)`D. `CICO_(2)` |
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Answer» Correct Answer - A Reducing agent is one which donate electrons. (a) `CO_(2)`, oxidation state of carbon in `CO_(2)` is `+4` which is the highest oxidation state of carbon. `therefore CO_(2)` cannot act as reducing agent. (b) `SO_(2)`, oxidatino state of sulphur in `SO_(2)` is `+4`. The highest oxidation state of sulphur is `+6`. `therefore SO_(2)` can act as reducing agent. (c) `NO_(2)`, oxidation state of nitrogen in `NO_(2)` is `+4` The highest oxidation state of nitrogen is `+5`. `therefore NO_(2)` can act as reducing agent. (d) `CIO_(2)`, oxidation state of chlorine in `CIO_(2)` is `+4`. The highest oxidation state of chlorine is `+7`. `therefore CIO_(2)` can act as reducing agent. |
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| 528. |
Assertion (A): `O_(3)` can act as an oxidising agent as wll as a reducing agent, but `SO_(2)` can act only as an oxidant. Reason (R ): The oxidation number of `O` in `O_(3)` is zero, and the oxidiation number of `S` in `SO_(2)` is `+4`.A. If both `(A)` and `(R )` are correct and `(R )` is the correct explanation of `(A)`.B. If both `(A)` and `(R )` are correct but `(R )` is not the correct explanation of `(A)`.C. If `(A)` is correct but `(R )` is incorrect.D. If both `(A)` and `(R )` are incorrect. |
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Answer» Correct Answer - D Correct (A): `SO_(2)` can act both as an oxidising and a reducing agent. `O_(3)` can act only as an oxidant. Reason: The oxidation number of `O` in `O_(3)` is zero. It can only decrease from zero to `-1` or `-2` but cannot increase to `+2`. Therefore, it can act as an oxidant only. In `SO_(2)`, the oxidation number of `S` is `+4`. It can have a minimum oxidation number of `-2` and maximum of `+6`. Its oxidation number either decreases or increases, and hence, it can act both as an oxidising and a reducing agent. |
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| 529. |
Select the reaction which describes the existence of `I_(2)O_(5)(s)` as `(IO_(2)^(+))(IO_(3)^(-))` :A. `I_(2)O_(5)+HFrarrHIO_(2)+FIO_(3)`B. `I_(2)O_(5)+HFrarrIO_(2)F+HIO_(3)`C. `I_(2)O_(5)+HFrarrHOI+IO_(4)F`D. `I_(2)O_(5)+HFrarrIOF+HIO_(4)` |
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Answer» Correct Answer - b |
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| 530. |
In `FeCr_(2)O_(4)` , the oxidation numbers of Fe and Cr are :A. `+2` and `+3`B. `0` and `+2`C. `+2` and `+6`D. `+3` and `+6` |
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Answer» Correct Answer - a |
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| 531. |
Which of the following compounds can be oxidised further with a strog oxidising agent?A. `CrO_(3)`B. `Al_(2)O_(3)`C. `SO_(2)`D. `MnO_(3)` |
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Answer» Correct Answer - C::D `overset(+6)(CrO_(3)` (Maximum oxidation state, cannot be oxidised further). b. `overset(+3)(Al_(2))O_(3)`(Maximum oxidation state, cannot be oxidised further) c. `overset(+4)(SO_(2))rarroverset(+6)(SO)_(4)^(2-)` (Can be oxidised further) d. `overset(+6)(Mn)O_(3)rarroverset(+7)(Mn)O_(4)^(ө)` (Can be oxidised further). |
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| 532. |
Dichloroacetic acid `(CHCI_2COOH)` is oxidised to `CO_(2),H_(2)O` and `CI_(2)` by 600meq of an oxidising agent. Same amount of ammonia to form ammonium dichloroacetate:A. `0.0167`B. `0.1`C. `0.3`D. `0.6` |
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Answer» Correct Answer - b |
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| 533. |
A sample which conains exactly 0.5 g of uranium in the form of `U^(4+)` . The total uranium is allowed to oxidized by 50 ml of `KMnO_(4)` . The reaction taking place is `U^(4+) + KMnO_(4) + H_(2)O to UO_(2)^(2+) + Mn^(2+) +H_(2)O^(+)` Find the concentration of `KMnO_(4)` required for the above purpose [U=238]A. 0.0336 MB. 0.0084 MC. 0.0168 MD. 0.0672 M |
| Answer» Correct Answer - C | |
| 534. |
If equal volume of 1M `KMnO_(4)` and 1M`K_(2)Cr_(2)O_(7)` solution are used to react with `Fe^(2+)` oxidized will be :A. more by `K_(2)Cr_(2)O_(7)`B. more by `KMnO_(4)`C. equal in both casesD. `Fe^(2+)` cannot be oxidized |
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Answer» Correct Answer - a |
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| 535. |
`0.45 g` of acid (mol. Wt.`=90`) was exactly neutralized by `20 ml` of `0.5(M) NaOH`. The basicity of the given acid isA. `1`B. `2`C. `3`D. `4` |
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Answer» Correct Answer - B milli equations of acid `=` milli equation of base `(0.45)/(90)xxbasicity=20xx0.5xx10^(-3)` `basicity=(90xx20xx0.5xx10^(-3))/(0.45)` `=2000xx10^(-3)=2` |
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| 536. |
Why is standard hydrogen electrode called reversible electrode? |
| Answer» A standard hydrogen electrode is called reversible electrode because it can act both as anode as well as cathode in an electrochemical cell | |
| 537. |
Which of the following is a disproportionation reaction?A. `Cl_(2(g))+2OH_((aq))^(-)rarrClO_((aq))^(-)+Cl_((aq))^(-)+H_(2)O_((l))`B. `Cl_(2(g))+2I_((aq))^(-)rarr 2Cl_((aq))^(-)+I_(2(s))`C. `2Fe_((s))+3H_(2)O_((l))overset(Delta)rarr Fe_(2)O_(3(s))+3H_(2(g))`D. `2H_(2)O_((l))+2F_(2(g))rarr 4HF_((aq))+O_(2(g))` |
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Answer» Correct Answer - A `overset(0)Cl_(2(g))+2OH_((aq))^(-)rarr overset(+1)(Cl)O_((aq))^(-)+overset(-1)Cl_((aq))^(-)+H_(2)O_((l))` Chlorine is simultaneously reduced and oxidised. |
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| 538. |
Why is anode negatively charged in an electrochemical cell? |
| Answer» Anode is negatively charged in and electrochemical because electrons are released at this electrode | |
| 539. |
Which of the following is a decreasing order of oxidation states of the central atoms?A. `PCl_(5), HIO_(4), Cl_(2)O_(7)^(2-), Cl_(2)O`B. `Cr_(2)O_(7)^(2-), Cl_(2)O, HIO_(4), PCl_(5)`C. `HIO_(4), Cr_(2)O_(7)^(2-), PCl_(5), Cl_(2)O`D. `Cr_(2)O_(7)^(2-), HIO_(4), Cl_(2)O, PCl_(5)` |
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Answer» Correct Answer - C `Cl_(2)O rarr 2x+1(-2)=0 rArr x=+1` `Cr_(2)O_(7)^(2-) rarr 2x+7(-2)=-2rArr x = +6` `HIO_(4) rarr +1+x+4(-2)=0 rArr x = +7` `PCl_(5) rarr x + (-5) = 0 rArr x = +5` |
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| 540. |
Consider the elements: `Cs, Ne, I` and `F` a. Identify the element that exhibits only negative oxidation state. b. Identify the element that exhibits only positive oxidation state. c. Identify the element that exhibits both positive and negative oxidation states. d. Identify the element which exhibits neither the negative nor does the positive oxidation state. |
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Answer» (a) F exhibits only negative oxidation state of `-1` . Cs exhibits positive oxidation state of `+1` . (c) I exhibits both positive and negative oxidation states . It exhibits oxidation states of `-1 , +1 , +3 , +5 ` and `+7` (d) The oxidation state of Ne is zero . It exhibits neither nor positive oxidation states . |
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| 541. |
Match column I and column II for the oxidation states of the central atoms. |
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Answer» Correct Answer - `A.to(4)" "B.to(5)" "C.to(3)" "D.to(1)` `A.to(4)" "B.to(5)" "C.to(3)" "D.to(1)` Suppose that x be the oxidation states of central atoms A. Oxidation number of Cr in `Cr_(2)O_(7)^(2-)` `2x+7(-2)=-2` `2x-14=-2` `2x=+12` `x=+6` B. Oxidation number of Mn in `MnO_(4)^(-)` `x+4(-2)=-1` `x-8=-1` `x=+7` C. Oxidation number of V in `VO_(3)^(-)` `x+3(-2)=-1` `x-6=-1` `x=+5` D. Oxidation number of Fe in `FeF_(6)^(3-)` `x+6(-1)=-3` `x-6=-3` `x=+3` |
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| 542. |
Which of the following is not an example of redox reaction?A. `CuO + H_(2) to Cu + H_(2)O`B. `Fe_(2)O_(3) + 3CO to 2Fe + 3CO_(2)`C. `2K + F_(2) to 2KF`D. `Cl_(2) + 6OH^(-) - 5Cl^(-) + CIO_(3)^(-) + 3H_(2)O` |
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Answer» Correct Answer - D Following are the examples of redox reaction (a) `CuO + H_(2) to Cu + H_(2)O` (b) `Fe_(2)O_(3) + 3CO to 2Fe + 3CO_(2)` ( c) `2K + F_(2) to 2KF` Option (d ) is not an example of redox reaction. |
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| 543. |
Which is not an example disproportionation reaction?A. `3H_(3)PO_(2) to 2H_(3)PO_(3) + PH_(3)`B. `HCHO + OH^(-) - HCOO^(-) + CH_(3)OH`C. `NH_(4)NO_(3) to N_(2)O + 2H_(2)O`D. `Cl_(2) + 6OH^(-) -5Cl^(-) + CIO_(3)^(-) + 3H_(2)O` |
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Answer» Correct Answer - C N of `NH_(4)^(+)` is oxidised and N of `NO_(4)^(-)` is reduced. |
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| 544. |
Balance the following chemical reactions (by ion electron method) (a) `C_(2)H_(5)OH+MnO_(4)^(Ө) rarr CH_(3)COO^(Ө) +MnO_(2)+H_(2)O+overset(Ө) (OH)` (b) `[Fe(CN)_(6)]^(3-_ + N_(2)H_(4) + overset(Ө) (OH)rarr [Fe(CN_(6))]^(4-) + N_(2)+H_(2)O` (c ) `CN^(Ө) + MnO_(4)^(Ө) +H_(2)O rarr MnO_(2)+CNO^(Ө) + overset(Ө) (OH)` (d) `CuO+NH_(3) rarr Cu+N_(2)+H_(2)O` (e) `HI+HNO_(3) rarr I_(2) + NO+H_(2)O` (f) `H_(2)S+SO_(2)rarrS+H_(2)O` |
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Answer» Correct Answer - A a. Basic medium `4H_(2)O+cancel(3e^(-))+MnO_(4)^(ө)rarrMnO_(2)+2H_(2)O+4overset(ө)OH]xx4` `{:(x-8,-1,x-4,=,0),(x,7,x,=,4):}` `5overset(ө)OH+H_(2)O+C_(2)H_(5)OHrarrCH_(3)COO^(ө)+cancel(4e^(-))+5H_(2)O]xx3` ` {:(2x+6-2=0,,2x+3-4=-1,,),(x=7,-,2x=0,,):}/ul(4MNO_(4)^(ө)+3C_(2)H_(5)OHrarr4MnO_(2)+3CHOO^(ө)+overset(ө)OH+4H_(2)O` b. Basic medium `4overset(ө)OH_N_(2)H_(4)rarrN_(2)+cancel(4e^(-))+4H_(2)O` `{:(2x+4=0,,2x=-0,,),(2x=-4,-,2x=0,,):}` `cancel(e^(-))+[Fe(CN)_(6)]^(3)rarr [Fe(overset(-1)(CN_(6)))]^(4)]xx4` `ulbar(4overset(ө)OH+N_(2)H_(4)+4[Fe(CN)_(6)]^(3-)rarrN_(2)+4[Fe(CN)_(6)]^(4-)+4H_(2)O` c. `4H_(2)Ocancel(3e)+MnO_(4)^(ө)rarrMnO_(2)+2H_(2)O+4overset(ө)OH]xx2` `{:(x-8=-1,x-4=0,,,),(x=7,x=4,,,):}` `2overset(ө)OH+H_(2)O+CN^(ө)rarrCNO^(ө)+cancel(2e)+2H_(2)O]xx3` `{:(x-3=-1,x-3=-2=-1,,,),(x=2,x=4,,,):}` `ulbar(H_(2)O+2MnO_(4)+3CN^(ө)rarr2MnO_(2)+3CNO^(ө)+2overset(ө)OH)` d. `2NH_(3)-ltN_(2)+cancel(6e^(-))+cancel(6H^(o+))` `2x+6=0, 2x=0` `2x= -6` `cancel(2H^(o+))+cancel(2e^(-))+CuOrarrCu+H_(2)O]xx3` `x-2=0, x=0` `x=2` `ulbar(2NH_(3)+3CuOrarrN_(2)+3Cu+3H_(2)O)` e. `2HIrarrI_(2)+cancel(2e^(-))+cancel(2H^(o+))]xx3` `2+2x=0,2x=0` `2x= -2` `3H^(o+)+3e^(-)+HNO_(3) -lt NO+2H_(2)O]xx2` `1+x-6=0, x-2=0` `x=5, x=2` `ulbar(6HI+2HNO_(3)rarr3I_(2)+2NO+4H_(2)O)` f. `H_(2)SrarrS+cancel(2^(e-))+cancel(2H^(o+))]xx2` `2+x=0, x=0` `x=-2` `calcel(4H^(o+))+cancel(4e^(-))+SO_(2)rarrS+2H_(2)O` `x-4=0, x=0` `ulbar(2H_(2)S+SO_(2)rarr3S+2H_(2)O`. |
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| 545. |
Consider the following reaction, `{:(CHO" "COO^(-)),("| "+OH^(-) rarr "|"),(CHO" "CH_(2)OH):}` Select the incorrect statement.A. It is not a disproportionation reaction.B. It is intramolecular redox reaction.C. `OH^(-)` is a reducing as well as oxidising agent.D. `{:(CHO),("|"),(CHO):}` is a reducing as well as oxidising agent. |
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Answer» Correct Answer - C One CHO is oxidised to `CO O^(-)` and one CHO is reduced to `CH_(2)OH`. Thus, it is not a disproportionation reaction. It is intramolecular redox reaction. Thus, options (a) and (b) are true and `{:(CHO),("|"),(CHO):}` is reducing as well as oxidising agent. Thus, (d) is also true. Thus, (c) is incorrect. |
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| 546. |
The oxidation number of carboxylic carbon atom in `CH_(3)COOH` isA. `+2`B. `+4`C. `+1`D. `+3` |
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Answer» Correct Answer - D `COOH:x-4+1= 0 implies x=3` Oxidation state of `C "in" COOH= +3` |
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| 547. |
The oxidation number and covalency of sulphur in the sulphur molecule `(S_(8))` are respectively:A. 0 and 2B. `+6 and 8`C. 0 and 8D. `+6 and 2` |
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Answer» Correct Answer - A O.N. of S in `S_(8)` = zero Covalency of S in `S_(8)=2` |
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| 548. |
Which of the following is not a disproportionation reaction ?A. `P_(4)+overset(ө)OHrarrH_(2)PO_(2)^(ө)+PH_(3)`B. `Cl_(2)+overset(ө)OHrarrCl^(ө)+ClO^(ө)`C. `2H_(2)O_(2)rarr2H_(2)O+O_(2)`D. `2H_(2)O_(2)rarr2H_(2)O+O_(2)` |
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Answer» Correct Answer - D Disproportionation involve simultaneous oxidation and reduction of the same atom in a molecule. |
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| 549. |
Which of the following is not an intramolecular redox reaction?A. `NH_(4)NO_(2)rarrN_(2)+2H_(2)O`B. `2Mn_(2)O_(7)rarr4MnO_(2)+3O_(2)`C. `2KCIO_(3)rarr2KCl+3o_(2)`D. `2H_(2)O_(2)rarr2H_(2)O+O_(2)` |
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Answer» Correct Answer - D Intramolecular redox change involves oxidation of one atom and reduction of the other atom within a molecule. |
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| 550. |
Oxidation state of oxygen atom in potassium superoxide isA. ZeroB. `-1//2`C. `-1`D. `-2` |
| Answer» Correct Answer - B | |