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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.
| 2. |
Ionisation enthalpy of litium is520kJ"mol"^(-1) How much energy in joules must be needed to convert all atoms of lithium to ions present in 7 mg of lithium vapours? |
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Answer» 74.3 J Energy needed for the ionisation of `7xx10^(-3)g` of Li VAPOUR `=520/7xx7xx10^(-3)=520J` |
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| 3. |
Ionisation enthalpy of chlorine is "13 eV atom"^(-1) Electron gain enthalpy of chlorine is -"348kJmol"^(-1) and if this energy is used for the conversion of Cl(g) rarr Cl^(+)(g), how many ions can be obtained? |
| Answer» SOLUTION :`1.67xx10^(22)` | |
| 4. |
IUPAC name of following compound is (CH_(3))_(3) C - CH_(2) - COOH |
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Answer» 2,2-dimethylbutanoic ACID |
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| 5. |
Ionisation enthalpy is lowest for: |
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Answer» INERT gases |
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| 6. |
Ionisation enthalpy decreases down the group in noble gases. Why ? |
| Answer» SOLUTION :DUE to INCREASE in ATOMIC SIZE. | |
| 7. |
IUPAC name of following compound is (CH_(3))_(2)CH-underset(C(CH_(3))_(3)"")underset(" |")(C Cl-CH(CH_(3))_(2)) |
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Answer» 3-chloro-3, 4-dimetyl -3-(2-methyl-2-propyl) PENTANE |
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| 8. |
Ionisation enthalpies of Ce, Pr and Nd are higher than Th, Pa and U. Why? |
| Answer» SOLUTION :In the beginning when 5f orbitals begin to be OCCUPIED, they penetrate LESS into the inner core of electrons and so 5f-electrons are more effectively shielded from the nuclear charge than 4f-electrons in lanthanoids. Hence, outer electrons in ACTINOIDS are easily available for chemical bonding and so Th, pa and U have lower ionization ENTHALPIES. | |
| 9. |
Ionisation enthalpies of Ce, Pr and Nd are higher than Th, Pa and U. Why ? |
| Answer» Solution :Ce, PR and Nd BELONG to4f series ( langthanoids) wheras Th, Pa and U belong to 5f series ( actinoids). When filling of 4f and 5f starts, ELECTRONS in 5f penetrate less intothe inner core. THEREFORE, they are more effectively shielded from the nuclear charge than 4f electrons of langthanoids. As a result, outer electrons of 5f series experience less force of attraction by the nucleus and hence have LOWER ionization enthalpies. | |
| 10. |
Ionisation enthalphy of group - 16 elements decreases down the group Why? |
| Answer» SOLUTION :It is DUE to INCREASE in SIZE. | |
| 11. |
Ionisation energy of He^(+) is 19.6xx10^(-18)J"atom"^(-1). The energy of first stationary state (n=1) of Li^(2+) is |
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Answer» `-2.2xx10^(-15)"atom"^(-1)` `:.`I.E of Hatom `=(19.6xx10^(-18))/4` `=4.9xx10^(-18)J"atom"^(-1)` I.E of `LI^(2-)` ion = I.E. of H atom `xx(3)^(2)` |
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| 12. |
IUPAC name of following compound is (CH_(3))_(2)N-C_(2)H_(5) |
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Answer» ethyl methylmethanamine |
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| 13. |
Ionisation energy of He^(+) is 19.6xx10^(-18)J"atom"^(-1). The energy of the first stationary state (n = 1) of Li^(2+) is |
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Answer» `4.41xx10^(-16)J"ATOM"^(-1)` |
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| 14. |
IUPACname of following compound is (CH_(3))_(2) CHOOC_(2)H_(5) |
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Answer» ethylisobutanoate |
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| 15. |
Ionisation energy of Al=5137 kJ "mole"^(-1) (DeltaH) hydration of Al^(3+) = -4665 kJ "mole"^(-1). (DeltaH)_("hydration") for Cl^(-)=-381 kJ "mole"^(-1). Which of the following statements is correct? |
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Answer» `AlCl_(3)` WOULD remain covalent in AQUEOUS solution |
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| 16. |
Ionisation energy and electron affinity of fluorine are respectively 17.42 and 3.45 eV. Calculate electronegativity of fluorine atom. |
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Answer» `= (17.42 +3.45)/(2) = 10.435` THEREFORE, electronegativity on Pauling's SCALE `(chi_(P)) = (10.435)/(2.8) = 3.726` |
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| 17. |
Ionisation depends upon |
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Answer» Pressure |
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| 18. |
IUPAC name of following compound is C_(2)H_(5) - COOCH(CH_(3))_(2) |
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Answer» isopropylpropanoate |
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| 19. |
Ionisation energies of Ni and Pt in Kj/mol are given below {:("",IE_1 + IF_2,IE_3 + IE_4),(Ni,2.49,8.80),(Pt,2.60,6.70):} So the correct statment is |
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Answer» Ni(Il) compounds TEND to be thermodynamically more stable than Pt(II) |
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| 20. |
ionisation constant of CH_(3)COOH is 1.7xx10^(-5)and concentration of H^(+) is 3.4xx10^(-4). Then the initial concentration of CH_(3)COOH molecules is : |
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Answer» `3.4xx10^(-4)` If `alpha` is the INITIAL CONCENTRATION of `CH_(3)COOH`, then at equilibrium. `(alpha-3.4xx10^(-4)) ""3.4xx10^(-4) ""3.4xx10^(-4)` `K=((3.4xx10^(-4))xx(3.4xx10^(-4)))/((alpha-3.4xx10^(-4)))=1.7xx10^(-5)` `(alpha-3.4xx10^(-4))=((3.4xx10^(-4))^(2))/(1.7xx10^(-5))` `=6.8xx10^(-3)` `THEREFORE alpha = 6.8xx10^(-3)+3.4xx10^(-4)~~ 6.8xx10^(-3)` |
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| 21. |
Ionic solids, with Schottky defects, contain in their structure: |
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Answer» Equal NUMBER of cation and ANION VACANCIES |
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| 22. |
Ionic solids with Schottky defect may contain in their structure |
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Answer» CATION VACANCIES only |
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| 23. |
IUPAC name of following compoud is CH_3-CH_2-oversetoverset(CH_3)|CH-CH_2CH_2OH |
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Answer» 5-ethyl -3-methylpentan-1-ol |
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| 25. |
Ionic solids with Schottky defects contain in their structure: |
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Answer» Equal number of CATIONS and ANION VACANCIES |
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| 26. |
Ionic solids with Schottky defects contain in their structure : |
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Answer» EQUAL NUMBER of CATIONS and anion vacancies |
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| 27. |
Ionic solids, which have anionic vacancies due to metal excess defect develop colour. Explain with the help of suitable example. |
| Answer» Solution :Taking the example of NaCl, when its crystals are heated in presence of sodium vapour some chloride ion leave their lattice sites to combine with sodium to form NaCl. For this reaction to occur Na atoms lose electrons to form `Na^(+)` ions. The electron that has been released diffuses into the crystal to occupy the ANION vacancies created by `Cl^(-)` ions. The crystal now has EXCESS of sodium. The sites occupied by unpaired electrons are called F-centres. They impart yellow colour to the crystal because they ABSORB ENERGY from the visible light and get EXCITED. | |
| 29. |
IUPAC name of [Fe(CN)_(6)]^(4-) is |
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Answer» ferrocyanide |
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| 30. |
IUPAC name of ethyl isopropyl ketone is |
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Answer» 4-methylpent 3-one |
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| 31. |
IUPACnameof ethyl amineis |
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Answer» ETHYL METHANAMINE |
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| 32. |
Ionic solids conduct electricity in molten state but not in solid state. Explain. |
| Answer» Solution :In molten STATE, ions of the ionic solid are FREE to move. So it can conduct ELECTRICITY due to the MOVEMENT of ions. But in the solid state the ions are fixed in their POSITIONS and have no freedoom of movement. So in the solid state they do not conduct electricity. | |
| 33. |
IUPAC name of ethyl t-butyl ether is |
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Answer» 2-ethoxypropane |
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| 34. |
Ionic solids conduct electricity in molten state but not in solid state, Explain. |
| Answer» SOLUTION :In the molten state, ionic solids dissociate to give free IONS and hence can conduct electricity. However in the SOLID state, as the ions are not free to move but remain held together by strong ELECTROSTATIC forces of attraction, so they cannot conduct electricity in the solid state. | |
| 35. |
IUPAC name of diacetone amine is |
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Answer» 2-methyl -4-ketopentan-2-amine |
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| 36. |
Ionic solids conduct electricity in mollten state but not in solid state. Explain. |
| Answer» Solution :In the molten state, ionic solids DISSOCIATE to give freeions and HENCE can conduct electricity. However in the solid state, as the ions are not FREE to move but remain held TOGETHER by strong electrostatic FORCES of attraction, so they cannot conduct electricity in the solid state. | |
| 37. |
IUPAC name of ethyl isopropyl ether |
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Answer» 2-ethoxypropane |
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| 38. |
Ionic solids are characterised by: |
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Answer» Good CONDUCTIVITY in SOLID state |
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| 39. |
IUPAC name of dehydration product of compound 'X' which is obtained on condensation of two molecules of acetone in dilute NaOH solution is |
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Answer» diacetone alcohol |
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| 40. |
Ionic solid B^+A^(-) crystallizes in rock salt type of structure.1.296 gm ionic solid salt B^+A^(-) is dissolved in water to make one litre solution.The pH of the solution is measured to be 6.0.if the value of face diagonal in the unit cell of B^+A^(-) be 600sqrt2 pm.Calculate the density of ionic solid in gm/cc.(T=298 K, K_b "for" BOH "is" 10^(-6),(Avogadro Number =6.0xx10^(23))) |
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Answer» `:. C=1.296/("MOLAR MASS")=1/100 " " implies ` molar mass of salt =129.6 For rock salt, `600sqrt2=sqrt2a` a=600 pm=`600xx10^(-10) cm` effective number of formula units z=4 Now density `=Z/N_A (M/a^3)=4/(6.0xx10^23)[129.6/((600)^3xx10^(-30))]=4` gm/cc. |
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| 41. |
Ionic salts on dissolution in a solvent shows: |
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Answer» A DECREASE in the VISCOSITY of the liquid |
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| 43. |
IUPAC name of DDT is 2,2-bis (p-chlorophenyl)-1,1,1 -trichloroethane. How many reactive chlorine atoms are there in the compound? |
Answer»  The CHLORINE atoms which is not DIRECTLY attached to the RING, will be more REACTIVE. |
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| 44. |
IUPAC name of DDT is |
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Answer» <P>1,1,1 -TRICHLORO -2,2 -bis (4- chloropheny1 ) ethane |
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| 45. |
Ionic product of water increass if : |
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Answer» PRESSURE is REDUCED |
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| 46. |
IUPAC name of Crotonaldehyde is pent-3-enal. True / False |
| Answer» SOLUTION :but-2-enal | |
| 47. |
Ionic product of water increases when |
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Answer» PRESSURE DECREASES |
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| 48. |
IUPAC name of complex ion [CrCl_(2)(Ox)_(2)]^(3-) is |
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Answer» DICHLORODIOXALATOCHROMIUM (III) |
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| 49. |
Ionic product of water increases if….. |
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Answer» pressure is REDUCED |
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