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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. |
Nuclear isomerism is exhibited byA. Molecular hydrogenB. All diatomic moleculesC. All diatomic molecules having even Z-valuesD. All diatomic molecules having odd Z-values. |
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Answer» Correct Answer - D All diatomic molecules having odd Z values because these have resultant nuclear spin. |
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| 2. |
`XeF_(6)+PF_(5) to `A. `XeF_(6)`B. `[XeF]^(+)[PF_(6)]^(-)`C. `XeF_(4)`D. `[PF_(4)]^(+)[XeF_(3)]^(-)` |
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Answer» Correct Answer - B `PF_(5)` is a fluoride ion acceptor so it yields cationic species with xenon fluorides. `XeF_(2) + PF_(5) rarr [XeF]^(+)[PF_(6)]^(-)` |
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| 3. |
Boric acid can be successfully titrated against sodium hydroxide in the presence ofA. dil. HClB. glycerolC. glycineD. borax. |
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Answer» Correct Answer - B Glycerol, mannitol, catechol can be used. In presence of these, boric acid behaves as a strong acid and gives a sharp end point. |
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| 4. |
Helium is added to oxygen used by deep sea divers because :A. It is less soluble in blood than nitrogen at high pressureB. It is lighter than nitrogenC. It is readily miscible with oxygenD. It is less poisonous than nitrogen. |
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Answer» Correct Answer - A As Helium is less soluble in blood than nitrogen under pressure. So, `O_(2) + He` mixture is used by deep sea divers. |
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| 5. |
Which one of the following statements regarding helium is incorrect?A. It is used to fill gas balloons instead of hydrogen because it is lighter and non-inflammableB. It is used in gas-cooled nuclear reactorsC. It is used to produce and sustain powerful surperconducting magnetsD. It is used as a cryogenic agent for carrying out experiments at low temperatures. |
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Answer» Correct Answer - A Helium is not lighter than hydrogen. |
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| 6. |
Xenon does not form compounds withA. OxygenB. FluorineC. BromineD. None of these. |
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Answer» Correct Answer - C Xenon forms compounds only with oxygen and fluorine due to their small sizes and high electronegativities. |
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| 7. |
Which of the following noble gas is least polarisable ?A. HeB. XeC. ArD. Ne. |
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Answer» Correct Answer - A He with smallest electron cloud is least polarisable. |
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| 8. |
The noble gas whose ionization potential is closet to that of oxygen isA. HeB. ArC. KrD. Xe. |
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Answer» Correct Answer - D Oxygen has ionisation energy 1166 kJ/mole. Xenon has ionisation energy 1170 kJ/mole. |
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| 9. |
Which of the following reacts with `F_(2)` ?A. NeB. XeC. ArD. Kr. |
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Answer» Correct Answer - B::D Only water, para-quinol and phenol form clathrates with noble gases. |
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| 10. |
The element which has not yet been reacted with `F_(2)` isA. ArB. XeC. KrD. Rn. |
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Answer» Correct Answer - A There is no known compound of Ar and `F_(2)` yet. |
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| 11. |
In which of the following groups, when He is placed, its all the properties are satisfied ?A. With alkali gasesB. With halogensC. With inert gasesD. None of these. |
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Answer» Correct Answer - C He`(1s^(2))` in infact a s-block element. However, its properties resembles with noble gas placed in p-block. Therefore, He is placed in group 18 alongwith other noble gases. |
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| 12. |
Which of the following is an inert gas?A. `H_(2)`B. `O_(2)`C. `N_(2)`D. argon. |
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Answer» Correct Answer - D Argon is an inert gas. |
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| 13. |
Which of the following hydride is capable of showing conformations ?A. `CH_(4)`B. `B_(2)H_(6)`C. `NH_(2)-NH_(2)`D. None of these. |
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Answer» Correct Answer - C Free rotation around N-N bond is possible. |
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| 14. |
Which of the following is the correct sequence of the noble gases in their in the periodic table ?A. Ar, He, Kr, Ne, Rn, XeB. He, Ar, Ne, Kr, Xe, RnC. He, Ne, Kr, Ar, Xe, RnD. He, Ne, Ar, Kr, Xe, Rn. |
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Answer» Correct Answer - D Correct sequence of noble gases (down the group) is He, Ne, Ar, Kr, Xn, Rn. |
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| 15. |
Which of the following noble gases does not have an octer of electrons in its outermost shell ?A. NeonB. RadonC. ArgonD. Helium. |
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Answer» Correct Answer - D Helium has only two electrons in its valence shell. On the other hand all other noble gases have 8 electrons in their valence shell. |
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| 16. |
`P_(4)S_(3)` is isostructural and isosteric withA. `Bi_(7)^(3-)`B. `P_(7)^(3-)`C. `P_(4)O_(6)`D. `P_(2)O_(5)`. |
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Answer» Correct Answer - B `P_(4)S_(3)` has `15 xx 4 + 16 xx 3` = 108 electrons. Similarly `P_(7)^(3-)` has `15 xx 7 + 3` = 108 electrons. So both are isostructural and isosteric (same number of electrons). |
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| 17. |
Which of the following finds use as a superior thermometer liquid for high temperature measurement ?A. GalliumB. ThalliumC. ArsenicD. Mercury |
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Answer» Correct Answer - A Gallium has a low m.pt. `(29.8^(@)C)` and very high b.pt. `(2070^(@)C)`. So Gallium has the longest liquid range of any known substance and finds use as a thermometer liquid for high temperature measurement. |
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| 18. |
Urey and his co-workers evaporated liquid hydrogen near its triple point (13.9 K) under reduced pressure, when 4 litres of liquid hydrogen is reduced to only 1 ml which on spectroscopic study give fant lines in the spectrum. This is the due toA. `._(1)^(1)H`B. `._(1)^(2)H`C. `._(1)^(3)H`D. `H_(3)` |
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Answer» Correct Answer - B `._(1)H^(2)` Deuterium. |
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| 19. |
Liquid ammonia and Liquor ammonia areA. SameB. DifferentC. AllotropesD. None. |
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Answer» Correct Answer - B Liquid ammonia is ammonia gas liquified under pressure and Liquor ammonia is an aqueous solution of ammonia. |
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| 20. |
The atomicity of noble gases isA. 4B. 3C. 1D. 2 |
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Answer» Correct Answer - C Noble gases are monoatomic. These do not form diatomic molecules. |
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| 21. |
For the isolation of inert gases from air, the nitrogen and oxygen present are removed by nitrogen and oxygen present are removed by passing air over heatedA. Calcium carbideB. Copper metalC. Activated charcoalD. Finely divided mixture of Pt and Pd. |
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Answer» Correct Answer - A Oxygen and nitrogen present in air can be removed strongly heating calcium carbide. `CaC_(2) + N_(2) overset(Delta) rarr CaCN_(2) + C` `2C + O_(2) overset(Delta) rarr 2CO` |
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| 22. |
In ordinary incadescent and fluorscen lamps the gas filled along with nitrogen isA. NeB. ArC. KrD. He. |
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Answer» Correct Answer - B Argon is the cheapest noble gas. It provides an inert atmosphere. |
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| 23. |
Helium is subjected to electrical discharge. The following species is not present in the discharge tubeA. `He_(2)`B. `He^(+)`C. `HeHe^(+)`D. `He^(2+)`. |
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Answer» Correct Answer - A `He_(2)` does not exist. |
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| 24. |
In order to prevent the hot metal filament from getting burnt, when the electric current is switched on, the bulb is filled withA. `Cl_(2)`B. `H_(2)`C. `NH_(3)`D. An Inert gas. |
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Answer» Correct Answer - D Inert gas. |
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| 25. |
Xe shows oxidation states ofA. 2B. 4C. 6D. 8 |
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Answer» Correct Answer - A::B::C::D Xe shows oxidation states of 2 (in `XeF_(2)`), 4 (in `XeF_(4)`), 6 (in `XeF_(6)` and `XeO_(3)`), 8 (in `XeO_(6)^(4-)`). |
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| 26. |
The idea which prompted bartlett to prepare first ever compound of noble gas wasA. high bond energy of Xe-FB. low bond energy of F-F in `F_(2)` moleculesC. ionization energies of Oxygen and Xenon are almost similarD. None of these. |
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Answer» Correct Answer - C As ionisation energy and diameter of both oxygen and xenon are similar so Bartlett think that if oxygen can form compound with `PtF_(6)` i.e., `[O_(2)^(+)PtF_(6)^(-)]` then Xenon can also do so. |
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| 27. |
What is the oxidation number of `Xe` in `XeOF_(2)`? |
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Answer» Correct Answer - C Oxidation state of Xe in `XeOF_(2)` is + 4 [x - 2 + 2 (-1) = 0 or x = 4] |
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| 28. |
Which of the following structures is most likely for `XeOF_(4)` ?A. TetrahedralB. Square pyramidalC. Square planarD. Octahedral. |
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Answer» Correct Answer - B `XeOF_(4)-sp^(3)d^(2)` hybridisation. See structure in Brief Review. |
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| 29. |
Which of the following is least soluble in water ?A. HeliumB. NeonC. ArgonD. Krypton. |
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Answer» Correct Answer - A Down the group, the solubility of noble gases in water increases so helium is least soluble. |
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| 30. |
Noble gases are also known as aerogens becauseA. they are rarely found in atmosphereB. argon, a noble gas is the most abundant gas of the atmosphereC. they occur in airD. None of the above. |
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Answer» Correct Answer - C Although, it is true that argon is the most abundant inert gas in the atmosphere but noble gases are known as aerogens because of the fact that they occur in air. |
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| 31. |
The lifting power of helium is______of hydrogen.A. 0.8B. 0.74C. 0.92D. 0.99 |
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Answer» Correct Answer - C `92 %` |
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| 32. |
The formula of sodium perxenate is ______.A. `Na_(3)XeO_(6)`B. `Na_(4)XeO_(6)`C. `Na_(2)XeF_(8)`D. None. |
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Answer» Correct Answer - B `Na_(4)XeO_(6).XeO_(6)^(4-)` is called perxenate ion. |
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| 33. |
Which of the following fluorides of Xe has zero dipole moment ?A. `XeF_(2)`B. `XF_(6)`C. `XeF_(4)`D. Both A & C. |
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Answer» Correct Answer - D `XeF_(2)` has a linear structure `therefore` its dipole is zero. In `XeF_(4)`, the four F atoms be at the corners of a square `therefore` their individual bond moments cancel each other. Further, since the two lone pairs lie at axial positions `therefore` their dipole moments also cancel each other and hence `XeF_(4)` has zero dipole moment. The only structure which is not symmetrical is `XeF_(6)` which has a finite dipole moment. `therefore XeF_(2)` and `XeF_(4)` have zero dipole moments `therefore` option is true. |
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| 34. |
Perxenate ion isA. `XeO_(6)^(4-)`B. `HXeO_(4)^(-)`C. `XeO_(4)^(2-)`D. `XeO_(4)^(-)`. |
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Answer» Correct Answer - A Perxenate ion is `XeO_(6)^(4-)` since Xe has the maximum O.S of `+ delta` in this ion. |
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