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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.
| 1. |
Which element among d-block element has(i) the lowest melting point and (ii) the highest melting point |
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Answer» (i) As Hg has weakest interatomic interaction on account of no unparied electrons, `(n-1)d^(10)ns^(2)` available for bonding. (ii) As W has highest interatomic interaction on account of more number of unpareid electrons, `(n-1)d^(5)ns^(1)` available for bonding. |
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| 2. |
Name the (i) lightest and the (ii) heaviest element (in terms of density)among the transition elements. |
| Answer» Correct Answer - (i) Sc (ii) Os Ir | |
| 3. |
Which of the following halides react(s) with `AgNO_(3(aq))` to give a precipitate that dissolves in `Na_(2)S_(2)O_(3(aq))`A. HClB. HFC. HBrD. `HI` |
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Answer» Correct Answer - A::C::D |
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| 4. |
Uub is the symbol for the element with atomic number-A. 102B. 108C. 110D. 112 |
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Answer» Correct Answer - D `112` ununbium (Uub) |
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| 5. |
Potassium manganate `(K_2MnO_4)` is formed whenA. `Cl_(2)` is passed into an aqueous solution of `KMnO_(4)`B. `MnO_(2)` is fuesed with `KOH`C. Formaldehyde reacts with `KMnO_(4)` in the presence of strong alkaliD. `KMnO_(4)` reacts with conc. `H_(2)SO_(4)` |
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Answer» Correct Answer - 3 `MnO_(4)^(-)` is reduced to `MnO_(4)^(2-)` by `HCHO` in the presence of strong alkali |
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| 6. |
Which of the following can be employed for the conversion of potassium manganate to potassium permanganate?A. `O_(3)`B. `Cl_(2)`C. `CO_(2)`D. All. |
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Answer» Correct Answer - D `2K_(2)MnO_(4)+Cl_(2)to2KMnO_(4)+2KCl," "2K_(2)MnO_(4)+H_(2)O+O_(3)to2KMnO_(4)+2KOH+O_(2)` `3K_(2)MnO_(4)+2CO_(2)to2KMnO_(4)+MnO_(2)+2K_(2)CO_(3)` |
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| 7. |
Potassium manganate `(K_2MnO_4)` is formed whenA. chlorine is passed into aqueous `KMnO_(4)` solutionB. manganese dioxide is fused with KOH in airC. formaldehyde reacts with potassium permanganate in the presence of strong alkaliD. potassium permanganate reaction with conc. `H_(2)SO_(4)` |
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Answer» Correct Answer - B::C |
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| 8. |
Pick out the correct statement from the following: 1. Cobalt (III) is more stable in octahedral complexes. 2. Zinc forms coloured ions or complexes 3. Most of the d-block elements and their compounds are ferromagnetic. ltBrgt 4. Osmium shows (VIII) oxidation state 5. cobalt (II) is more stable in octahedral complexes.A. 1 and 2B. 1 and 3C. 2 and 4D. 1 and 4 |
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Answer» Correct Answer - D In `Co^(+3)` ion, electronic configuration `|Ar|_(18)3d^(6)4s^(0)`. For octahedral complex 4 unpaired electron get paired and in configuration become `t_(2g)^(6)eg^(0)` and hybridization `d^(2)sp^3` Os has maximum VIII oxidation state. |
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| 9. |
`{:("Element",Cr,Mn,Fe),(E^(underset(-)(o))(M^(2+)//M),-0.90V,-1.18V,-0.4V),(E^(underset(-)(o))(M^(3+)//M^(2+)),-0.41V,+1.57V,+0.8V):}` ltbr. Use this data to comment upon (i) the stability of `Fe^(3+)` and `Mn^(2+)` in acid solutions, (ii) The ease with which iron can be oxidised as compared to the similar process for either Cr or Mn metals. |
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Answer» (i) `Mn^(2+)` is more stable than `Fe^(3+)` (ii) The order of getitng oxidised is `Mn gt Cr gt Fe`. |
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| 10. |
Why is the `E^(Theta)` value for the `Mn^(3+)//Mn^(2+)` couple much postive than for `Cr^(3+)//Cr^(2+) or Fe^(3+)//Fe^(2+)`? Example |
| Answer» Much larger third ionisation energy of Mn (change from `3d^(5)` to `3d^(4)`) is responsible for hits. This also explains why the +3 state of Mn is of little importance. | |
| 11. |
`S_(1) : Mn^(2+)` compounds more stable than `Fe^(2+)` towards oxidation to their `+3` state. `S_(2)` : Titanium and copper both in the first series of transition metals exhibits `+1` oxidation state most frequently. `S_(3) : Cu^(+)` ions is stable in aqueous solutions. `S_(4)` : The `E^(0)` value for the `Mn^(3+)//Mn^(2+)` couple much more positive than that for `Cr^(3+)//Cr^(2+)` or `Fe^(3+)//Fe^(2+)`,A. TTFTB. TFFTC. TFTTD. FFTF |
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Answer» Correct Answer - B `S_(1):` It is because `Mn^(2+)` has `3d^(5)` configuration which has extra stability. `S_(2):` Not titatnium but copper, because with +1 oxidation state an extra stable configuraiton `3d^(10)` results `S_(3):`It is not stable as it undergoes disproportionation `2Cu^(+)(aq)toCu^(2+)(aq)+Cu(s).` The `E^(underline(o))` value for this is favourable. `S_(4)`: Much larger third ionisation energy of Mn (where the required change is `d^(5)` to `d^(4)`) is mainly responsible for this. |
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| 12. |
The outermost electrinic configuration of Cr is ________ |
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Answer» Correct Answer - `3d^(2)4s^(1)` |
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| 13. |
The less stable oxidation states of Cr are:A. `Cr^(2+)`B. `Cr^(3+)`C. `Cr^(4+)`D. `Cr^(5+)` |
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Answer» Correct Answer - A::C::D `Cr^(3+)` is most stable because in aqueous solution it has higher CFSE on account of half filled `t_(2g)^(3)` energy level of 3d orbitals in octahedral spliting. |
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| 14. |
The maximum oxidation state shown by `V(Z=23),Cr(Z=24),Co(Z=27),Sc(Z=21)`, are respectivelyA. `+5,+5,+3,+2`B. `+5,+6,+3,+3`C. `+5,+4,+5,+2`D. `+5,+3,+2,+1` |
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Answer» Correct Answer - 2 Electronic configuration of`" "V=[Ar]3d^(3)4s^(2)" "+5` Electronic configuration of `" "Cr=[Ar]3d^(5)4s^(1)" "+6` Electronic configuration of `" Co=[Ar]3d^(7)4s^(2)" "+3` Half filled`t_(2g)^(6)` has higher CFSE and thus `+3` O.S. is stable Electronic configuration of `Sc=[Ar]3d^(1)4s^(2)" "+3` |
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| 15. |
One of the consituents of German silver isA. AgB. CuC. MgD. Al |
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Answer» Correct Answer - B |
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| 16. |
German silver is an alloy of copper and:A. `Zn+Ni`B. `Al+Ag`C. `Zn+Ag`D. `Sn+Zn` |
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Answer» Correct Answer - A German silver contains `Cu=60%,Z=20%,` and Ni=20% |
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| 17. |
In which of the following reactions, reaction of silver with the given acids lead to the formation of compound & silver, along with liberation of gas?A. `Ag+"dilute "HNO_(3)`B. `Ag+conc." "HNO_(3)`C. `Ag+"conc. "H_(2)SO_(4)`D. All of these. |
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Answer» Correct Answer - D `Ag+` dilute `HNO_(3)toAgNO_(3)+NO(g)` Ag+conc. `HNO_(3)toAgNO_(3)+NO_(2)(g)` `Ag+` conc `H_(2)SO_(4)toAg_(2)SO_(4)+SO_(2)(g)` |
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| 18. |
Why silver chloride is used I photochromic spectacles?A. Silver halides darken I light owing to photochemical decompositionB. silver halides produced elemental silver in light.C. If the halogen produced is kept is closed proximity to finely divided silver c hloride, the silver metal is formed.D. All of these. |
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Answer» Correct Answer - D `AgCloverset(hv) to underset(("black"))(Agdarr))+1//2Cl_(2)` If source of light is removed, we get back agce and blacknem due to Ag removed. |
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| 19. |
In the dichromate dianion,A. `4 Cr-O` bonds are equivalentB. `6 Cr-O` bonds are equivalentC. all `Cr-O` bonds are equivalentD. all `Cr-O` bonds are non-equivalent |
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Answer» Correct Answer - B |
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| 20. |
`(NH_4)_2Cr_2O_7` on heating gives a gas which is also given byA. heating `NH_(4)NO_(2)`B. heating `NH_(4)NO_(3)`C. `Mg_(3)N_(2) + H_(2)O`D. `Na("comp.") + H_(2)O_(2)` |
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Answer» Correct Answer - A |
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| 21. |
Which one of the following alloys contains some of the lanthanoid metals ?A. MischmetalB. BrassC. BronzeD. Ziggler-Natta |
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Answer» Correct Answer - 1 Mischmetall contains lanthanoid metal `(95%)`and iron `(5%)` and traces of `S,C,Ca` and `Al`. |
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| 22. |
Which of the following is a lanthanide ?A. CuriumB. CaliformiumC. UraniumD. Europium |
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Answer» Correct Answer - 4 `(1),(2)` and `(3)` are actinoids where as `(4)` europium is lanthanide. |
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| 23. |
Which one of the following arrangements does not represent the correct order of the property stated against it?A. `V^(2+) lt Cr^(2+) lt Mn^(2+) lt Fe^(2)` : paramagnetic behaviourB. `Ni^(2+) lt Co^(2+) lt Fe^(2+) lt Mn^(2)` : ionic sizeC. `Co^(3+) lt Fe^(3+) lt Cr^(3+) lt Sc^(3+)` : stability in aqueous solutionD. `Sc lt Ti lt Cr lt Mn` : number of oxidation states. |
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Answer» Correct Answer - A |
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| 24. |
Which of the following combination will produce `H_(2)` gas ?A. Fe metal and conc. `HNO_(3)`B. Cu metal and conc. `HNO_(3)`C. Au metal and NaCN (aq) in the presence of airD. Zn metal and NaOH (aq) |
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Answer» Correct Answer - D |
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| 25. |
In the following reaction, ZnO is respectively as a/an (i) `ZnO+Na_(2)O rarr Na_(2)ZnO_(2)` (ii) `ZnO+CO_(2)rarr ZnCO_(3)`A. base and acidB. base and baseC. acid and acidD. acid and base |
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Answer» Correct Answer - D |
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| 26. |
Which of the following reactions represents " developing"in photography ?A. `AgNO_(3)+NaBrrarrAgBr+NaNO_(3)`B. `AgNO_(3)+2Na_(2)S_(2)O+_(3)rarrNa_(3)[Ag(S_(2)O_(3))_(2)+NaBr`C. `C_(6)H_(4)(OH)_(2)+2AgBr^(**)rarrC_(6)H_(4)O_(2)+2HBr+2Ag`D. `AgBr+2NH_(3)rarr[Ag(NH_(3))_(2)]Br` |
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Answer» Correct Answer - 3 Developing involves the decomposition of `AgBr` to `Ag`. `2AgBr^(**)(s)+2OH^(-)(aq)+C_(6)H_(4)(OH)_(2)rarr2Ag(s)+2HH_(2)O+2Br^(-)(aq)+C_(6)H_(4)O_(2)(aq)` Where `AgBr^(**)` represents a molecule of AgBr exposed to light. |
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| 27. |
Why is AgBr used in photography? |
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Answer» Out of all silver halides, AgBr is most sensitive to light and under goes photo reduction to metalic silver instantaneously on exposure to light. `2AgBrto2Ag+Br_(2)` Unexposed AgBr can be dissolved out in h ypo `(Na_(2)S_(2)O_(3))` solution. `AgBr+2Na_(2)S_(2)O_(3)toNa_(3)[Ag(S_(2)O_(3))_(2)]+NaBr.` |
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| 28. |
Match the reaction in column I with nature of the reactions/type of the products In Column II. . |
| Answer» (A-p,s),(B-r),(C-p,q),(D-p) | |
| 29. |
A compound is yellow when hot and white when cold. The compound is:A. `Al_(2)O_(3)`B. `PbO`C. `CaO`D. `ZnO` |
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Answer» Correct Answer - D It is a white powder which becomes yellow on heating due to change in the structure of lattice (due to cation excess defect) but again turns white on cooling. |
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| 30. |
Which of the following reaction(s) is/are used for the preparation of anhydrous `FeCl_(3)`?A. `FeCl_(3)6H_(2)O+6SOCl_(2)toFeCl_(3)+12HCl+6SO_(2)`B. `Fe(OH)_(3)darr+3HClto FeCl_(3)+3H_(2)O`C. `2Fe+HCl(aq.)+Cl_(2)to2FeCl_(3)+2H_(2)`D. `2Fe+3Cl_(2)(dry)to2FeCl_(3)` |
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Answer» Correct Answer - A::D (A) Anhydrous, (B) Hydrated, (C) Hydrated, (D) Anhydrous |
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| 31. |
When `K_(4)[Fe(CN)_(6)]` is added to `FeCl_(3)` , the complex compound formed is:A. `Fe_(3)[Fe(CN)_(6)]_(4)`B. `Fe_(4)[Fe(CN)_(6)]_(3)`C. `K_(2)Fe[Fe(CN)_(6)]`D. `K_(2)Fe_(2)[Fe(CN)_(6)]_(2)` |
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Answer» Correct Answer - B `Fe^(3+)+[Fe(CN)_(6)]^(4-)toFe_(4)[Fe(CN)_(6)]_(3)` (prussian blue). |
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| 32. |
`FeCl_(3).6H_(2)O` is actually:A. `[Fe(H_(2)O)_(6)]Cl_(3)`B. `[Fe(H_(2)O)_(5)Cl]Cl_(2).H_(2)O`C. `[Fe(H_(2)O)_(4)Cl_(2)]Cl.2H_(2)O`D. `[Fe(H_(2)O)_(3)Cl_(3)].3H_(2)O` |
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Answer» Correct Answer - C Hydrated `FeCl_(3)` exists as `[Fe(H_(2)O)_(4)Cl_(2)]Cl.H_(2)O`, it is factual. |
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| 33. |
Which of the following will not be oxidised by `O_(3)`?A. `KI`B. `FeSO_(4)`C. `KMnO_(4)`D. `K_(2)MnO_(4)` |
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Answer» Correct Answer - C |
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| 34. |
The compound that gets oxidised even on exposure to atmosphere is:A. `Co_(2)(SO_(4))_(3)`B. `NiSO_(4)`C. `KMnO_(4)`D. `FeSO_(4)` |
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Answer» Correct Answer - D `4FeSO_(4)+2H_(2)O+O_(2)to4Fe(OH).SO_(4)`(basic ferric sulphate). |
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| 35. |
The +3 ion of which one of the following has half filled 4f subshell?A. LaB. LuC. GdD. Ac |
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Answer» Correct Answer - C `Gd^(3+):[Xe]4f^(7)` |
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| 36. |
`E^(Theta)` values for the couples `Cr^(3+)//Cr^(2+)` and `Mn^(3+)//Mn^(2+)` -0.41 and +1.51 volts respectively. Considering these values select the correct option from the following statementsA. `Cr^(2+)` acts as a reducing agent and `Mn^(3+)` acts as an oxidising agent in their aqueous solutions.B. `Cr^(2+)` (aq). Is more stable than `Cr^(3+)(aq.)`C. `Mn^(3+)(aq)` is more stable than `Mn^(2+)(aq.)`D. None of these. |
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Answer» Correct Answer - A `Cr^(3+)+e^(-)toCr^(2+),E^(Theta)=-0.41` votls and `Mn^(3+)+e^(-)toMn^(2+)+E^(Theta)=+1.51`volts this shows that `Cr^(2+)` is unstable and has a tendency to acquire more stable `Cr^(3+)` state by acting as a reducing agent. On the other hand `Mn^(3+)` is unstable and is reduced to more stable `Mn^(2+)` state. |
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| 37. |
On heating `KMnO_(4)`, one among the following is not formed:A. `K_(2)MnO_(4)`B. `O_(2)`C. `MnO_(2)`D. `MnO`. |
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Answer» Correct Answer - D `2KMnO_(4)overset(750K)toK_(2)MnO_(4)+MnO_(2)+O_(2)`. |
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| 38. |
On heating `ZnCl_(2).2H_(2)O`, the compounds obtained is:A. `ZnCl_(2)`B. `Zn(OH)Cl`C. `Zn(OH)_(2)`D. `Zn` |
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Answer» Correct Answer - B `ZnCl_(2).2H_(2)Ooverset(Delta)toZn(OH)Cl+HCl+H_(2)O`. |
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| 39. |
`Mn^(2+)` can be oxidised to `MnO_4(ɵ)` by `_______`(SnO_2,PbO_2,BaO_2`). |
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Answer» Correct Answer - `PbO_(2)` |
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| 40. |
Which of the following ions are colourless in the aqueous solutions ?A. `La^(3+)` and `Lu^(3+)`B. `Nd^(3+)` and `Pm^(3+)`C. `Ce^(3+)` and `Pt^(3+)`D. `Sm^(3+)` and `Eu^(3+)` |
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Answer» Correct Answer - 1 Most of the trivalent lanthanoid of compounds except that of `La^(3+)` and `Lu^(3+)` are coloured both in the solide state and in the aqueous solution. The colour of these ions can be attributed due to the presence of unpaired `f-`electrons. |
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| 41. |
Which of the following ions has the maximum magnetic moment in aqueous solution ?A. `Mn^(2+)`B. `Fe^(2+)`C. `Co^(2+)`D. `Cr^(2+)` |
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Answer» Correct Answer - 1 `(1)` Valence shell electron configuration of `Mn^(2+)` is `3d^(5)`, therefore, has the maximum number of unparied electrons equal to 5 and , therefore, has maxium magnetic moment. `(2)` Valence shell electron configuratino of `Fe^(2+)` is `3d^(6)`, therefore, has the maximum number of unpaired electrons equal to 4. `(3)` Valence shell electron configuration of `Co^(2+)` is `3d^(7)`, therefore, has the maximum number of unpaired electrons equal to 3. `(4)` Valence shell electron configuration of `Cr^(2+)` is `3d^(4)`, therefore, has the maximum number of unparied electrons equal to 4. |
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| 42. |
Aqueous solution of which of the following ions is green?A. `V^(2+)`B. `V^(3+)`C. `VO^(2+)`D. `VO_(2)^+` |
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Answer» Correct Answer - B `{:((A)" "V^(2+),"Violet",(B)" "V^(3+),"Green"),((C)" "VO^(2+),"blue",(D)" "VO_(2)^(+),"yellow"):}` |
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| 43. |
Which of the following statement(s) is/are correct ?A. The electronic configuration of Cr is `[Ar] 3d^(2) 4s^(1)` (Atomic number of Cr = 24)B. The magnetic quantum number may have a negative valueC. In silver atom, 23 electrons have a spin of one type and 24 of the opposite type (Atomic number of Ag = 47)D. The oxidation state of nitrogen in `HN_(3)` is `-3` |
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Answer» Correct Answer - B::C |
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| 44. |
Which of the following statement(s) is/are correct when a mixture of NaCl and `K_(2)Cr_(2)O_(7)` is genetly warmed with conc. `H_(2)SO_(4)` ?A. A deep red vapours is formedB. Vapours when passed into NaOH solution gives a yellow solution of `Na_(2)CrO_(4)`C. Chlorine gas is evolvedD. Chromyl chloride is formed |
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Answer» Correct Answer - A::B::D |
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| 45. |
CO forms a volatile carbonyl complex with which of the following metals ?A. NaB. SnC. NiD. Hg |
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Answer» Correct Answer - 3 `Ni(CO)_(4)` No complex with others. |
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| 46. |
In the reaction,`2CuCl_(2)+2H_(2)O+SO_(2)toA+H_(2)SO_(4)+2HCl,A ` isA. CuClB. `Cu`C. `CuSO_(4)`D. `CuS` |
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Answer» Correct Answer - A `2CuCl_(2)+SO_(2)+2H_(2)Oto2CuCl+2CHl+H_(2)SO_(4)`. |
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| 47. |
Match List I with List II and select the correct answer using the code given below below the lists `:` `{:("List"-I,,"List"-II),((a)CuCl_(2)","2H_(2)O,,(I)"Colourless and diamagnetic" ),((b)Cu_(2)Cl_(2),,(II)"Green and paramagnetic"),((c ) CuO,,(III)"Calamine"),((d)ZnCO_(3),,(IV)Black and basic"):}` Code:A. `{:(,a,b,c,d),(,II,I,IV,III):}`B. `{:(,a,b,c,d),(,III,I,II,IV):}`C. `{:(,a,b,c,d),(,IV,II,III,I):} `D. `{:(,a,b,c,d),(,I,II,III,IV):} ` |
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Answer» Correct Answer - 1 `{:(CuCl_(2).2H_(2)O,,Cu^(+2)rarr3d^(9),"Green and paramagnetic"),(Cu_(2)Cl_(2),,Cu^(+1)rarr3d^(10),"Colourless and diamagnetic"),(CuO,,"Black and basic",),(ZnCO_(3),,"Calamine",):}` |
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| 48. |
Match List I with List II and select the correct answer using the code given below the lists `:` `{:("List"-I("Reaction"),,"List"-II("Proces")),(a.NH_(4)Br+AgNO_(3)rarrAgBr+NH_(4)NO_(3),,p."Preparation of sensitive film" ),(b.C_(6)H_(4)(OH)_(2)+2AgBrrarr 2Ag+C_(6)H_(4)O_(2)+2HBr,,q."Developing of the film"),(c. 2Na_(2)S_(2)O_(3)+AgBrrarrNa_(3)[Ag(S_(2)O_(3))_(2)]+2NaBr,,r."Fixing of he film"),(d.AuCl_(3)+3Ag rarr3AgCl+Au,,s."Toning process"):}` Code:A. `{:(,a,b,c,d),(,p,q,r,s):} `B. `{:(,a,b,c,d),(,p,r,q,s):} `C. `{:(,a,b,c,d),(,p,s,q,r):} `D. `{:(,a,b,c,d),(,q,s,p,r):} ` |
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Answer» Correct Answer - A `{:(a.,NH_(4)+AgNO_(3)rarrAgBr+NH_(4)NO_(3),("Preparation of sensitive film")),(b.,C_(6)H_(4)(OH)_(2)+2AgBrrarr2Ag+C_(6)H_(4)O_(2)+2HBr,("Developing of the film")),(c.,2Na_(2)S_(2)O_(2)+AgBr rarrNa_(3)[Ag(S_(2)O_(3))_(2)]+2NaBr,("Fixing of the folm")),(d.,AuCl_(3)+3Ag rarr3AgCl+Au,("Toning process")):}` |
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| 49. |
Why it is not advisable `KMnO_(4)` in cold and concentrated `H_(2)SO_(4)`? |
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Answer» Because explosive `Mn_(2)O_(7)` is formed. `2KMnO_(4)+2H_(2)SO_(4)toMn_(2)O_(7)+2KHSO_(4)+H_(2)O` `2Mn_(2)O_(7)to4MnO_(2)+3O_(2)`. |
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| 50. |
Among the following statement choose the true or false statements(s). A) `K_(2)Cr_(2)O_(7)` on heating with charcoal gives metallic potassium and `Cr_(2)O_(3)` B) On heating in current of `H_(2)` the crystalline `KMnO_(4)` is converted into `KOH` and `Mn_(3)O_(4)` C) Hydrated ferric chloride on treatment with `2-2`-dimethoxypropane gives anhydrous ferric chloride. |
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Answer» Correct Answer - (a). False (b) False (c) True (a). `K_(2)Cr_(2)O_(7)++2C("charcoal")overset(Delta)toCr_(2)O_(3)+K_(2)CO_(3)+Couarr` (b). `2KMnO_(4)+5H_(2)overset(Delta)to2KOH+2MnO+4H_(2)O` (c). `FeCl_(3)+6H_(2)O+6CH_(3)-underset(OCH_(3))underset(|)overset(OCH_(3))overset(|)(C)-CH_(3)toFeCl_(3)("anhydrous")+12CH_(3)OH+6CH_(3)COCH_(3)`. |
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