This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 3. |
The oxidation number of B is Na_2B_4O_7 is +3 . Is the statement correct ? |
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Answer» |
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| 4. |
The oxidation number of an element in a compound is evaluated on the basis of certain rules. Which of the following is incorrect in this respect ? |
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Answer» The OXIDATION number of hydrogen is always +1. |
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| 5. |
The oxidation number of an element in compound is evaluated on the basic of certain rules which of the following rules is not correct in this respect ? |
| Answer» Solution :O.N of H is always +1 is a WRONG statement SINCE it is +1 hydrogen HALIDES -1 in hydrdes and zero in the `H_(2)` molecule | |
| 6. |
The oxidation number of an element in a compound decides its nature to acts as oxidant or reductant. Oxidation number is defined and the residual charge which an atom has or appears to have in a molecule whenal other atoms are removed from the molecule as ions. Oxidation number is frequently used interchangebly with oxidation state. The stock notations of oxidation number are based on the periodic property-electronegativity. An atom in a molecule can be assigned positive, negative or zero oxidation number by considering its environment. In few cases, oxidation number can evenn be fractional. Oxidation number of Y in YBa_(2)Cu_(2)O_(7) is +3, then oxidation number of Cu is: |
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Answer» SOLUTION :`3 +2xx2+3xxa+7xx(-2)=0` `:.a=+7//3` |
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| 7. |
The oxidation number of an element in a compound decides its nature to acts as oxidant or reductant. Oxidation number is defined and the residual charge which an atom has or appears to have in a molecule whenal other atoms are removed from the molecule as ions. Oxidation number is frequently used interchangebly with oxidation state. The stock notations of oxidation number are based on the periodic property-electronegativity. An atom in a molecule can be assigned positive, negative or zero oxidation number by considering its environment. In few cases, oxidation number can evenn be fractional. Oxidation number of oxygen in K_(2)O, K_(2)O_(2),KO_(2),KO_(3) are in the order: |
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Answer» `KO_3ltKO_3 ltK_2O_2 LT K_2O` |
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| 8. |
The oxidation number of an element in a compound decides its nature to act as oxidant or reductant. Oxidation number is defined as the residual charge which an atom has or appears to have in a molecule when all other atoms are removed from the molecule as ions. Oxidation number is frequently used interchangebly with oxidation state. The stock notations of oxidation numbers are based on the periodic property - electronegativity. An atom in a molecule can be assigned positive, negative or zero oxidation number by considering its environment. In few cases, oxidation number can even be fractional. Maximum oxidation state shown by Os, Ru and Xe in their compounds is : |
| Answer» SOLUTION :In `OsO_4 and RuO_4 and XeO_6^(4-)` | |
| 9. |
The oxidation nuber fo an atom in a given species (molecule ion, or free atom ) is the . |
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Answer» formal charge of the atom |
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| 10. |
The oxidant which is used as an antiseptic is ______ |
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Answer» `KBrO_(3)` |
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| 11. |
The oxalic acid is added in test tube and this reaction Fe_((aq))^(3+) + SCN_((aq))^(-) hArr [Fe(SCN)]_((g))^(2+)equilibrium, steered and remain the solution than what will the change in colour of solution ? |
| Answer» Solution :The intensity of red colour of solution is DECREASE because the oxalate ion, `C_2O_4^(2-)`of oxalic acid is reacts with `Fe^(3+)` ion and decrease the concentration of `Fe^(3+)`. The reaction should be forward an red colour containing `[Fe(SCN)]_((AQ))^(2+)`is decrease, the red colour decreases. | |
| 13. |
The overall effect of respiration is similar to that of "_______________". |
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Answer» photosynthesis |
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| 14. |
The outermost electronic configuration of the element with highest value of electron affinity is ……… |
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Answer» `NS^(2)np^(3)` |
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| 15. |
The outermost electronic configuration of most electropositive element is |
| Answer» Answer :A | |
| 16. |
The outermost electronic ccnfiguration of manganese (at.no.=25)is……………. |
| Answer» SOLUTION :`3D^(5)4S^(2)` | |
| 17. |
The outer shell configuration of the most electronegative element is |
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Answer» `NS^(2) np^(3)` |
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| 18. |
The outer electronic configuration of someelements are given below : (i)3s^(2) 3p^(3) (ii) 3d^(5) 4s^(1) (iii) 3s^(2) 3p^(6) 4s^(2) (iv) 5d^(1) 6s^(2) (v) 4f^(1) 5d^(1) 6s^(2) Stateof which blockof theperiodic tableeach of thetheseelementsbelongs |
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Answer» <P> SOLUTION :(i) p, (ii) d, (III) s, (iv) d, (v) F |
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| 20. |
The outerelectronicconfigurationof Gd (AtomicNo. 64) is |
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Answer» `4f^(3) 5D^(3)6s^(2)` |
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| 21. |
The outer electronic configuration of alkaline earth metals is |
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Answer» `ns^2` |
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| 22. |
Theouterelectronicconfigurationof alkalineearthmetalsis ______. |
| Answer» Answer :A | |
| 23. |
the outcome of internal liquid of gel on shaking is called : |
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Answer» SYNERESIS |
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| 24. |
The outcome material from Solvay process is |
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Answer» `Na_(2)CO_(3).10H_(2)O` |
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| 25. |
The ortho/para-directing group among the following is |
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Answer» COOH |
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| 26. |
The origin of charge on colloidal solution is |
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Answer» Frictional rubbing |
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| 27. |
The orientation of hybrid orbitals is tetrahderal in |
| Answer» Answer :A | |
| 28. |
The orientation of electron pairsand the shape of molecule are different in |
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Answer» `BeCl_(2)` |
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| 29. |
The organic solvent used in differential extraction is…….in water |
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Answer» |
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| 30. |
The ore having two different metal atoms is |
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Answer» haeatite |
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| 31. |
The order of the oxidation state of the phosphorus atom in H_(3)PO_(2),H_(3)PO_(4),H_(3)PO_(3),andH_(4)P_(2)O_(6) is |
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Answer» <P>`H_(3)PO_(4)gtH_(3)PO_(2)gtH_(3)PO_(3)gtH_(4)O_(2)O_(6)` |
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| 32. |
The order of stabiliyt of the following carboncation is….. |
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Answer» `III gt II gt I` The benzylic cation is EXTRA stabilizaed by resonance. (I) `CH_(2) = CH- overset(OPLUS)(C )H_(2) harr overset(oplus)(C )H_(2)-CH= CH_(2)` alylic cation is stable by resonance (II) `CH_(3)-CH_(2) - overset(+)(C )H_(2)` It is least stable as resonance is not possible in it |
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| 33. |
The order of stability of the following tautomeric compounds is : CH_(2)=overset(OH)overset(|)C-CH_(2)-underset(I)overset(O)overset(||)C-CH_(3) hArr Ch_(3)-overset(O)overset(||)C-CH_(2)-underset(II)overset(O)overset(||)C-CH_(3) hArr CH_(3)-overset(OH)overset(|)C=CH-underset(III)overset(O)overset(||)C-CH_(3) |
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Answer» `III GT II gt I` |
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| 34. |
The order of stability of the following tautomeric compound is CH_(2) = oversetoverset(C ) - CH_(2) - oversetoverset(O)("||")C - CH_(3) hArr CH_(3) - oversetoverset(O)("||")C-CH_(2) - oversetoverset(O)("||")C - CH_(3)hArr CH_(3) - oversetoverset(OH)(|)C = CH - oversetoverset(O)("||")C - CH_(3) |
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Answer» III `gt` II `gt` I This is more stable because of INTRA molecular hydrogen bonding and conjugation of L.P and `pi` - electrons and between `pi`- electrons |
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| 35. |
The order of stability of thefollowing cabocations CH_(2) = CH- CH_(2)^(+), CH_(3)CH_(2)CH_(2)^(+),C_(6)H_(5)CH_(2)^(+) is |
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Answer» `III gt II gt I` Benzyl `gt` Allyl `gt I^(@)` |
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| 36. |
The order of stability of the following carbocations : |
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Answer» `III GT II gt I` |
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| 37. |
The order of stability of the following carbanions is |
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Answer» <P>`I gt II gt III gt IV` |
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| 38. |
The order of stability of the carbonium ion is- |
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Answer» `1^(@) gt 2^(@) gt 3^(@)` |
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| 39. |
The order of stability of dihalides of Ge, Pb and Sn is |
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Answer» `GeCl_(2) GT SnCl_(2) gt PbCl_(2)` |
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| 40. |
The order of solubility of lithium halides in nonpolar solvents follows the order : |
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Answer» `LiI gt LIBR gt LICL gt LIF` `LiI gt liBr gt LiCl gt LiF` |
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| 41. |
The orderof screening effect of electrons of s, p, d and f orbitals of a givenshell of anatom on itsouter shellelectrons is : |
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Answer» `s GTP gt d gt f` |
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| 42. |
The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons is : |
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Answer» `s GT p gt dgt f` |
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| 43. |
The order of screening effect of electron of s, p, d and f orbits of a given shell of an atom on its outershell electrons is: |
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Answer» <P>s>p>d>f |
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| 44. |
The order of relative ease of formation of various ions is |
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Answer» `F^(-)GTO^(-2)gtN^(-3)` |
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| 45. |
The order of reactivity of the following compounds in electrophilic monochlorinatic the most favorable position is |
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Answer» I lt II lt IV lt III |
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| 46. |
The order of reactivity of the following alkyl halides for a S_(N)2 reaction is |
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Answer» `R -F GT R-Cl gt R-Br gt R-I` |
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| 47. |
The order of reactivity of the followin alcohols towards conc. HCl is |
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Answer» `I gt II gt III gt IV` `F -CH_(2)-underset((I))(overset(+)(CH))- CH_(3)` `underset((II)) (F-CH_(2)-CH_(2)-overset(+)(CH)-CH_(3))` `underset((III))(CH_(3)-overset(+)(CH)-CH_(3))` `underset((IV))(C_(6)H_(5)-overset(+)(CH_(2))` The relative stabilities of carbocations and hence the order of reactivity of corresponding alcohols is `IV gt III gt II gt I`. The greater stability of carbocation (IV) is due to resonance. Carbocation II is a `2^(@)` carbocation and as such is quite stable. The lesser stability of carbocation I and II is due to the `-I` effect of F. ELECTRON with-drawing effect of F is more in case of carbocation I as in this case F is nearer to the carbon CARRYING +ve charge. |
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| 48. |
The order of reactivity of halogen acids for reaction with C_(2)H_(5)OH is |
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Answer» `HCl gt HBr gt HI` |
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| 49. |
The order of reactivity of differeent hydrogen halides (HCI,HI,HBr)is ………………. |
| Answer» SOLUTION :`HI GT HBrgt HCI` | |
| 50. |
The order of reactivity of alkenes,underset"I"((CH_3)_2C=CH_2). underset"II"(CH_3CH=CH_2), underset"III"(CH_2=CH_2) when subjected to acid-catalysed hydration is |
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Answer» I gt II gt III |
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