94420 + Interview Questions in Chemistry in Class 12 Page 581 InterviewSolution

29001.	The law of multiple proportions are illustrated by which pair of compounds?
Answer» NACL and NABR `H_2O` AND D_2O` NAOH and KOH `SO_2 and S_O3` ANSWER :D

Discussion

29002.	The law of multiple proportions is illustrated by the pair of compounds.
Answer» SODIUM CHLORIDE and sodium BROMIDE water and HEAVY water sulphur DIOXIDE and sulphur trioxide magnesium hydroxide and magnesium oxide. Answer :C

Discussion

29003.	The law of mass action was enunciated by
Answer» Guldberg and WAAGE Badenstein Birthelot GRAHAM ANSWER :A

Discussion

29004.	The law of multiple proportion is lillustrated by the pair of compounds
Answer» sodium chlordie and sodium BROMIDE water and heavy water sulphur DIOXIDE and sulphur TRIOXIDE magnesium hydroxide and magnesium OXIDE Solution :The law of multipw proportion is illustrated by the pair of coompounds : `SO_(2) and SO_(3).`

Discussion

29005.	The law of multiple proportion may be illustrated by
Answer» KBR, KI `H_2O , D_2O` `CO , CO_2` `CAO , CaCO_3` SOLUTION :`H_2O , D_2O`

Discussion

29006.	The law of constant proportions was enunciated by:
Answer» Dalton Berthelot Avodadro Proust. ANSWER :D

Discussion

29007.	The law formulated by Dr. Nernst is
Answer» First LAW of THERMODYNAMICS SECOND law of thermodynamics Third law of thermodynamics Both (a) and (B) Answer :C

Discussion

29008.	The laughing gas is
Answer» `N_(2)O_(5)` `N_(2)O_(3)` `NO_(2)` `N_(2)O` ANSWER :D

Discussion

29009.	The lattice site in a pure crystal cannot be occupied by ........
Answer» MOLECULE ion electron atom Solution :In pure CRYSTALS, there is perfect arrangment of constituent particles such as atoms, ions or molecules. ELECTRONS only occupy LATTICE SITE if there is defect in a crystal.

Discussion

29010.	The lattice site in a pure crystal cannot be occupied by
Answer» molecule ion ELECTRON atom Solution :electron

Discussion

29011.	The lattice enthalpy of KI will be, if the enthalpy of (I) Delta H^- (KI) = -78.0 kcal mol^-1 (II) Ionisation energy of K to K^+ is 4.0 eV(III) Dissociation energy of I_2 is 28.0 kcal mol^-1 (IV) Sublimation energy of K is 20.0 kcal mol^-1(V) electron gain enthalpyfor I to I^- is -70.0 kcal mol^-1(VI) Sublimation energy of I_2 is 14.0 kcal mol^-1 (1 eV =23. 0 kcal mol^-1)
Answer» `+14.1 KJ mol^-1 ` `-14.1 kJ mol^-1 ` `-141 kJ mol^-1 ` `+141 kJ mol^-1 ` ANSWER :C

Discussion

29012.	The lattice points of a crystal of hydrogen iodide are occupied by :
Answer» HI molecules H atoms and I atoms `H^(+)`cations andanions `H_(2)` molecules and I2 molecules Solution :Since, HI is a covalent MOLECULE and crystallizes in face centred cubic (FCC) structure, HI molecules are present at the lattice points of the CRYSTAL.

Discussion

29013.	The lattice points of a crystal of hydrogen iodide are occupied by-
Answer» HI molecules H atoms and I atoms `H^(+)` CATIONS and `I^(-)` anions `H_(2) ` molecules and `I_(2)` molecules Answer :A

Discussion

29014.	The lattice enthalpy and hydration enthalpy of four compounds are given below {:("Compound","Lattice enthalpy","Hydration enthalpy"),(,("in kJ mol"^(-1)),("in kJ mol"^(-1))),(P,+780,-920),(Q,+1012,-812),(R,+828,-878),(S,+632,-600):}The pair of compounds which is soluble in water is
Answer» P and Q Q and R R and S P and R Solution :A compount is SOLUBLE in water when its hydration enthalpy is GREATER than its lattice enthalpy.

Discussion

29015.	The lattice energy order for lithium halide is :
Answer» `LiFgtLiClgtLiBrgtLil` `LIClgtLiFgtLiBrgtLiI` `LiBrgtLiClgtLiFgtLil` `LilgtLiBrgtLiClgtLiF` ANSWER :A

Discussion

29016.	The lattice energy of the lithium halides is in the following order
Answer» LiFgtLiClgtLiBrgtLiI LiClgtLiFgtLiBrgtLiI LiBrgtLiClgtLiFgtLiI LiIgtLiBrgtLiClgtLiF Solution :`LiF GT LiCl gt LiBr lt LII ` Lattice energy depends on the SIZE and charge of the ION.

Discussion

29017.	The lattice energy of solid NaCl is 180 kcal/mol. The dissolution of the solid in water in the form of ions is endotermic to the extent of 1 kcal/mol. If the solution energies of Na^(+) and Cl^(-) are in the ratio 6:5, What is the enthalpy of hydration of Na^(+) ion.
Answer» `-85.6` kcal/mol `-97.5` kcal/mol `82.6` kcal/mol `+100` kcal/mol. ANSWER :B

Discussion

29018.	The lattice energies of the oxides of Mg, Ca, Sr and Ba follow the order-
Answer» `CaOlt SrOlt BaOlt MgO` `CaOgt BaOgt SrOgt MgO` `MgO GT CaO gt SrOgt BAO` `BaO gt SrO gt CaOgt MgO` ANSWER :C

Discussion

29019.	The latent heats of fusion in J g^(-1) of five substances a (mol.mass = 18) , b(mol. mass = 20) , c (mol. mass = 30), d (mol. mass = 60) and e (mol. mass = 30) are respectively 80, 45, 90, 45, 45. Which of the following pair has same value of Delta H_("fusion ")
Answer» a ,C B ,E d ,e c, d ANSWER :D

Discussion

29020.	The latest technique used for the purification of organic compounds containing minute quantities is:
Answer» DISTILLATION Sublimation Chromatography Crystallisation Answer :C

Discussion

29021.	The latent heat of vapourisation of water is 9700 Cal/mole and if the b.p. is 100^(@)C, equllioscopic constant of water is
Answer» `0.513^(@)C` kg/mol `1.026^(@)C` kg/mol `10.26^(@)C` kg/mol `1.832^(@)C` kg/mol SOLUTION :`K_(b)=(M_(1)RT_(b)^(2))/(1000 DELTA H_(V))=(18xx1.987xx(373)^(2))/(1000xx9700)=0.513^(@)C`

Discussion

29022.	The latent heat of vaporisation of water at 100^(@) is 2257 (kJ)/(kg). The Delta H for the process H_(2)O(g) rarr H_(2)O(l) is very nearly
Answer» `+ 2257 J` `- 2257 J` `+ 40.7 kJ` `- 40.7 kJ` SOLUTION :`DELTA H` for process `= -2257 XX 18` `= - 40626` `= - 40.7 kJ`

Discussion

29023.	The latent heat of fusion of ice is 80 "cal"//g at 0^(@)C what is the freezing point of a solution of Kcl in water containing 7.45 grm of solute in 500 grm of water , assuming the salt is dissociated to the extent of 95%
Answer» `0.73^(@)C` `-0.73^(@)C` `272.27K` `273.73K` ANSWER :C

Discussion

29024.	The last member of inert gas elements is
Answer» HELIUM NEON ARGON RADON ANSWER :D

Discussion

29025.	The last member o inert gas family is
Answer» Krypton Radon Xenon Argon Answer :B

Discussion

29026.	The last member in each period of the periodic table is
Answer» An INERT GAS element A TRANSITION element A halogen An ALKALI metal Answer :A

Discussion

29027.	The last filled orbital in lanthanides is
Answer» 6S 5s 4s 3s Answer :A

Discussion

29028.	The last filled orbital in actinides is
Answer» 6S 7s 5s 4s Answer :B

Discussion

29029.	The last energy level of radon contains
Answer» 10 electrons 8 electrons 2 electrons 15 electrons Answer :B

Discussion

29030.	The last element of the P - block in 6^(th) period is representedby theouter most electronicconfiguration :
Answer» `7s^(2)7P^(6)` `5f^(14)6d^(10) 7s^(2)7p^(0)` `4f^(14)5D^(10)6s^(2)6p^(6)` `4f^(14)5d^(10)6s^(2)6p^(4)` Answer :C

Discussion

29031.	The last electron which entersthe atom of transition element is called
Answer» s - electron p - electron f- electron d - electron Solution :LAST `E^-` ENTERS into d-orbital , HENCE d-electron

Discussion

29032.	The last electron placed in the third(n=3) quantum shell for:
Answer» Kr Zn Cu Ca Answer :C

Discussion

29033.	The lassaigne's extract is boiled with dil.HNO_(3) before testing for halogens because
Answer» Silver HALIDES are soluble in `HNO_(3)` `Na_(2)S and NaCN` are DECOMPOSED by `HNO_(3)` `Ag_(2)S` is soluble in `HNO_(3)` AgCN is soluble in `HNO_(3)` SOLUTION :`Na_(2)S and NaCN`, formed during fusion with metallic sodium must be rmoved before adding `AgNO_(3)`, otherwise black ppt. due to `Na_(2)S` or white precipitate due to AgCN will be formed and thus white precipitate of AGCL will not be identified easily. `Na_(2)S+2AgNO_(3) to 2NaNO_(3)+underset("Black")(Ag_(2)S)darr` `NaCN+AgNO_(3) to NaNO_(3)+underset("white")(AgCN)darr` `NaCl+AgNO_(3) to NaNO_(3)+underset("white")(AgCl)darr` `Na_(2)S+2HNO_(3) to 2NaNO_(3)+H_(2)Suarr` `NaCN+HNO_(3) to NaNO_(3)+HCNuarr`

Discussion

29034.	The Lassaigne's extract is boiled with conc. HNO_(3)whiletesting for halogen. By doing so it
Answer» Increase the CONCENTRATION of `NO_(3)^(-)` Decomposes `Na_(2)S`and `NaCN` , if FORMED Helpsin the precipitation of `AgCl` Increase the SOLUBILITY product of `AgCl` Solution :N//A

Discussion

29035.	The largest group in Modern periodic table is
Answer» ANSWER :3

Discussion

29036.	The largest number of molecules is in:
Answer» 36 g of WATER 28 g of `CO_2` 46 g of `CH_3OH` 54 g of `N_2O_5` SOLUTION :34 g of water

Discussion

29037.	The largest number of molecules are in
Answer» `36 G H_2O` 28 g CO 46 g `C_2H_5OH` 54G `N_2O_5` ANSWER :A

Discussion

29038.	The largest diagonal in a cubic crystal of edge length a is
Answer» `SQRT(3A)` `sqrt2a` `sqrt3a` `sqrt(2a)` ANSWER :C

Discussion

29039.	The largest bond angle exists in:
Answer» `H_2Se` `H_2Te` `H_2O` `H_2S` ANSWER :B

Discussion

29040.	The largest bond angle is in:
Answer» `NH_3` `PH_3` `AsH_3` `SbH_3` ANSWER :A

Discussion

29041.	The large difference in boiling points of alcohols and ethers is due to ________ in alcohols.
Answer» SOLUTION :HYDROGEN BONDING.

Discussion

29042.	The lanthanum exhibits which of the following oxidation state ?
Answer» only `+2` `+2 and +3` only `+3` only `+3 and +4` ANSWER :D

Discussion

29043.	The lanthanoids show a regular decrease in atomic and ionic radii but this decrease in very small due ...................
Answer» SOLUTION :LANTHANOID CONTRACTION

Discussion

29044.	The Lanthanoids contraction is responsible for the fact that
Answer» ZR and Y have about the same radius Zr and NB have SIMILAR OXIDATION state Zr and Hf have about the same radius Zr and ZN have the same oxidation state Answer :C

Discussion

29045.	The lanthanoide which shows all i.e., +2,+3 and +4 oxidation state is
Answer» EUROPIUM SAMARIUM neodymium GADOLINIUM ANSWER :C

Discussion

29046.	The lanthanoide ion with e.c. 4 f^(14) 5d ^(0) 6s^(0) has tendecny to
Answer» under GOES REDUCTION GAIN ELECTRON lose electron all of these Answer :C

Discussion

29047.	The lanthanoide ion used as oxidizing agent is
Answer» `EU^(3+)` `Yb^(3+)and Ce ^(3+)` `Eu^(3+)and TB^(3+)` none of these Answer :D

Discussion

29048.	The lanthanoid elements than has the electronic configuration. [Xe] 4f^(1) 5d^(1) 6s^(2) is
Answer» LUTETIUM cerium yterbium GADOLINIUM ANSWER :D

Discussion

29049.	The Lanthanide ion that would show colour is
Answer» `SM^(3+)` `LA^(3+)` `Lu^(3+)` `GD^(3+)` ANSWER :A

Discussion

29050.	The lanthanoid contraction refers to :
Answer» valence electrons of the lanthanoid SERIES ionic RADIUS of the series the density of the series nuclear MASS of the series. Answer :B

Discussion

Explore topic-wise InterviewSolutions in .

The law of multiple proportions are illustrated by which pair of compounds?

The law of multiple proportions is illustrated by the pair of compounds.

The law of mass action was enunciated by

The law of multiple proportion is lillustrated by the pair of compounds

The law of multiple proportion may be illustrated by

The law of constant proportions was enunciated by:

The law formulated by Dr. Nernst is

The laughing gas is

The lattice site in a pure crystal cannot be occupied by ........

The lattice site in a pure crystal cannot be occupied by

The lattice points of a crystal of hydrogen iodide are occupied by :

The lattice points of a crystal of hydrogen iodide are occupied by-

The lattice enthalpy and hydration enthalpy of four compounds are given below {:("Compound","Lattice enthalpy","Hydration enthalpy"),(,("in kJ mol"^(-1)),("in kJ mol"^(-1))),(P,+780,-920),(Q,+1012,-812),(R,+828,-878),(S,+632,-600):}The pair of compounds which is soluble in water is

The lattice energy order for lithium halide is :

The lattice energy of the lithium halides is in the following order

The lattice energy of solid NaCl is 180 kcal/mol. The dissolution of the solid in water in the form of ions is endotermic to the extent of 1 kcal/mol. If the solution energies of Na^(+) and Cl^(-) are in the ratio 6:5, What is the enthalpy of hydration of Na^(+) ion.

The lattice energies of the oxides of Mg, Ca, Sr and Ba follow the order-

The latent heats of fusion in J g^(-1) of five substances a (mol.mass = 18) , b(mol. mass = 20) , c (mol. mass = 30), d (mol. mass = 60) and e (mol. mass = 30) are respectively 80, 45, 90, 45, 45. Which of the following pair has same value of Delta H_("fusion ")

The latest technique used for the purification of organic compounds containing minute quantities is:

The latent heat of vapourisation of water is 9700 Cal/mole and if the b.p. is 100^(@)C, equllioscopic constant of water is

The latent heat of vaporisation of water at 100^(@) is 2257 (kJ)/(kg). The Delta H for the process H_(2)O(g) rarr H_(2)O(l) is very nearly

The latent heat of fusion of ice is 80 "cal"//g at 0^(@)C what is the freezing point of a solution of Kcl in water containing 7.45 grm of solute in 500 grm of water , assuming the salt is dissociated to the extent of 95%

The last member of inert gas elements is

The last member o inert gas family is

The last member in each period of the periodic table is

The last filled orbital in lanthanides is

The last filled orbital in actinides is

The last energy level of radon contains

The last element of the P - block in 6^(th) period is representedby theouter most electronicconfiguration :

The last electron which entersthe atom of transition element is called

The last electron placed in the third(n=3) quantum shell for:

The lassaigne's extract is boiled with dil.HNO_(3) before testing for halogens because

The Lassaigne's extract is boiled with conc. HNO_(3)whiletesting for halogen. By doing so it

The largest group in Modern periodic table is

The largest number of molecules is in:

The largest number of molecules are in

The largest diagonal in a cubic crystal of edge length a is

The largest bond angle exists in:

The largest bond angle is in:

The large difference in boiling points of alcohols and ethers is due to ________ in alcohols.

The lanthanum exhibits which of the following oxidation state ?

The lanthanoids show a regular decrease in atomic and ionic radii but this decrease in very small due ...................

The Lanthanoids contraction is responsible for the fact that

The lanthanoide which shows all i.e., +2,+3 and +4 oxidation state is

The lanthanoide ion with e.c. 4 f^(14) 5d ^(0) 6s^(0) has tendecny to

The lanthanoide ion used as oxidizing agent is

The lanthanoid elements than has the electronic configuration. [Xe] 4f^(1) 5d^(1) 6s^(2) is

The Lanthanide ion that would show colour is

The lanthanoid contraction refers to :