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.
| 1. |
Non- stoichiometric metal deficiency is show in the salts of |
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Answer» all metals |
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| 2. |
Non-stoichiometric hydrides are |
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Answer» hydrides of all d-block elements |
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| 3. |
Non-stoichiometric cuprous oxide, Cu_2O can be prepared in laboratory. In this oxide, copper to oxygen ratio is slightly less than 2:1. Can you account for the fact that this substance is a p-type semiconductor ? |
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Answer» Solution :In `Cu_2O`,the number of`Cu^(+)` IONS have been replaced by `Cu^(2+)` ions. As a result, there is a CATIONIC vacancy in the crystal structure. The electrical neutrality is maintained by presence of `Cu^(2+)` ions that replace `Cu^(+)` ions as a result the hole is created. Thus, the conduction takes place by the presence of hole and HENCE it is p-type semiconductor. |
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| 4. |
Non-stoichiometric cuprous oxide, Cu_(2)O can be prepared in laboratory. In this oxide, copper to oxygen ratio is slightly less than 2 : 1. Can you account for the fact that this substance is a p-type semiconductor ? |
| Answer» Solution :As the RATIO is less than `2: 1`, it INDICATES that some `CU^(+)` ions have been replaced by `Cu^(2+)` ions. For every two `Cu^(+)` ions displaced from the lattice site, one `Cu^(2+)` ion will be replaced to maintain ELECTRICAL neutrality. Thus, for every `Cu^(2+)` in the lattice, one HOLE will be created. These positive holes will be responsible for conduction of electricity. Hence, it is a p-type conductor. | |
| 5. |
Non-stoichiometric cuprous oxide, Cu_(2)O can be prepared in laboratory. In this oxide, copper to oxygen ratio is slightly less than 2 : 1. Can you account for the fact that this substance is a p-type semi-conductor ? |
| Answer» Solution :SINCE the ratio of Cu: O in `Cu_(2)O` is less than 2: 1, THEREFORE, `Cu_(2)O` is non-stoichiometric crystal. This means that some Cut ions have been replaced by `Cu^(2+)` ions. To MAINTAIN electrical neutrality, every two `Cu^(2+)` ions will be replaced by one `Cu^(2+)`ION thereby creating a hole. Since the conduction will be due to the presence of these positive holes, it is a p-type semiconductor. | |
| 6. |
Non-stoichiometric compound Fe_(x)O (where 0.84ltxlt0.96) is formed due to metal deficiency defects in the crystal structure of FeO. The electrical neutrality of the crystal of Fe_(x)O is maintained because when one Fe^(2+) ion leaves the crystal- |
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Answer» one oxide ion in the form of `O_(2)(g)` LEAVES the crystal |
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| 7. |
Non-stoichiometric compounds are formed by |
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Answer» ALKALI METALS |
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| 8. |
Non stoichiometric compounds are formed by : |
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Answer» ALKALI metals |
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| 9. |
Non - sticking frying pans are coated with teflon which is polymer of |
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Answer» Ethylene |
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| 10. |
Non-Stick cookwares generally have a coating of a polymer, whose monomer is |
| Answer» Solution :`nCF_(2) = CF_(2) to + CF_(2) - CF_(2)+_(n)` Teflonis usedfor non-stick cookwares. | |
| 11. |
Non-sticking frying pans are coated with which polymer? |
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Answer» Ethylene |
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| 12. |
Non stick cook wares generally have a coating of a polymer, whose monomer is |
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Answer» ethane |
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| 14. |
Non reducing sugar end with suffix |
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Answer» oside |
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| 15. |
Non reacting gases have a tendency to mix with each other. This property is known is : |
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Answer» Diffusion |
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| 16. |
Non-polar molecule among the following is |
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Answer» `SF_4` |
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| 17. |
Non- polar molecule is: |
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Answer» `BCl_3` |
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| 18. |
Non-oxide ceramics can be |
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Answer» `B_(4)C` |
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| 19. |
Non-metals combine with oxygen to form usually |
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Answer» BASIC oxides |
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| 20. |
Non - lanthanoid atom is |
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Answer» LA |
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| 21. |
Non - ionogenic surfactants are |
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Answer»
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| 22. |
Non-ideal solutions exhibit either positive or negative deviations from Raoult's law. What arethese deviations and why are they caused ? Explain with one example for each type. |
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Answer» Solution : POSITIVE deviations : In this type of solutions, the total vapour pressure is more than that expectedfrom Raoult.s law, `DELTA V_( mix)` and `Delta H_( mix)`are always positive. Examples : acetone + benzene, ETHYL ALCOHOL + chloroform. Negative deviations : In this type of solutions, total pressure for any mole fraction is less than that according to Raoult.s law. For such solutions, `Delta V_(mix)` and `DeltaH_(mix)`are negative. Examples : benzene + chloroform, water + sulphuric acid. |
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| 23. |
Non-ideal solutions exhibit either positive or negative deviation from Raoult's law. What are these deviations and why are they caused? Explain with one example for each type. |
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Answer» Solution :`=+ve` DEVATION : Ethyl ALCOHOL and CYCLOHEXANE -ve DEVIATION : Water and nitric acid |
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| 24. |
Explain the following terms with suitable examples. Non-ionic detergents. |
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Answer» |
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| 26. |
Non - electrolyte colloidal surfactants is |
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Answer» `C_(12)H_(35) COONa` |
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| 28. |
Non- combustible hydride is: |
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Answer» `PH_3` |
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| 29. |
Non-directional orbital is: |
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Answer» 3s |
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| 30. |
Non-aromatic compound among the given compounds is |
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Answer»
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| 31. |
Noble gases were considered inert before 1962. Prior to this, Bartlett and Lohmann had previously used the highly ionization energy of O_(2) is 1165 " kJ mol"^(-1), which isalmost the same as the value of IE_(1) for Xe (1170 " kJ mol"^(-1)) . Experiments showed that when deep red PtE_(6) vapours were mixed with an equal volume of Xe, the gases combined immediately at room temperature to produce a yellow solid. Soon after this, it was found that Xe and F react directly to give Xe-fluorides. Choose the correct answer : The hybridisation state of Xe in XeOF_(4) is : |
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Answer» `sp^(3)` |
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| 32. |
Noble gases were considered inert before 1962. Prior to this, Bartlett and Lohmann had previously used the highly ionization energy of O_(2) is 1165 " kJ mol"^(-1), which isalmost the same as the value of IE_(1) for Xe (1170 " kJ mol"^(-1)) . Experiments showed that when deep red PtE_(6) vapours were mixed with an equal volume of Xe, the gases combined immediately at room temperature to produce a yellow solid. Soon after this, it was found that Xe and F react directly to give Xe-fluorides. Choose the correct answer : In what molar ratio must Xe and F_(2) combine to give XeF_(4) ? |
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Answer» `2 : 1` |
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| 33. |
Noble gases were considered inert before 1962. Prior to this, Bartlett and Lohmann had previously used the highly ionization energy of O_(2) is 1165 " kJ mol"^(-1), which isalmost the same as the value of IE_(1) for Xe (1170 " kJ mol"^(-1)) . Experiments showed that when deep red PtE_(6) vapours were mixed with an equal volume of Xe, the gases combined immediately at room temperature to produce a yellow solid. Soon after this, it was found that Xe and F react directly to give Xe-fluorides. Choose the correct answer : What was the yellow solid obtained by them ? |
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Answer» `[XeF_(2)]^(+) [PtF_(6)]^(-)` |
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| 34. |
Noble gases with the highest ionisation energy and greater solubility in water are respectively |
| Answer» Answer :D | |
| 35. |
Noble gases possess: |
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Answer» HIGHLY IONISATION potential |
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| 36. |
Noble gases have very low boiling points. Why? |
| Answer» SOLUTION :The boiling points of noble gases are very low since their atoms are held together by weak VAN der Waals FORCES of attraction. | |
| 37. |
Noble gases have very low boiling points. Why ? |
| Answer» Solution :Noble gases being monoatomic have no INTERATOMIC forces except WEAK dispersion forces and therefore, they are LIQUEFIED at very LOW temperatures. Hence, they have low boiling points. | |
| 39. |
Noble gases have very low boiling point. Why ? |
| Answer» Solution :DUE to WEAK DISPERSION force between their atoms. | |
| 40. |
Noble gases have very high ionisation enthalpy. Why ? |
| Answer» Solution :Due to stable ELECTRONIC configuration `(NS^(2) np^(6))`. | |
| 41. |
Noble gases have larger atomic size than the preceeding halogens because |
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Answer» They are gases |
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| 42. |
Noble gases have large positive values of electron gain enthalpy. Why ? |
| Answer» SOLUTION :Since noble gases have stable - ELECTRONIC configurations, they have no tendency to accept the ELECTRON. Therefore, they have HIGH `+ve` electron gain enthalpy. | |
| 43. |
Noble gases have |
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Answer» HIGH IONISATION ENTHALPY and more negative electron GAIN enthalpy. |
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| 44. |
Noble gases exists only in monoatomic state. This is due to |
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Answer» Non availability of UNPAIRED electrons |
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| 45. |
Noble gases do not occur in: |
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Answer» Nature |
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| 46. |
Noble gases do not react with other elements because: |
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Answer» They are monoatomic |
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| 47. |
Noble gases are used in discharge tubes to give different colours. The gas in Beacon lights for pilots used is? |
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Answer» Ar |
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| 49. |
Noble gases are used in discharge tubes to give different colours. Reddish-orange glow is due to |
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Answer» Ar |
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| 50. |
Noble gases are sparingly soluble in water, owing to |
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Answer» dipole-dipole interactions |
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