52671 + Interview Questions in Chemistry in Class 11

1.	In diborane the two H-B-H angles are nearly
Answer» `60^(@), 120^(@)` `95^(@), 120^(@)` `95^(@), 150^(@)` `120^(@), 180^(@)` SOLUTION :In diborane, `H_(t)-B-H_(t)` and `H_(b)-B-H_(b)` BOND angles are `120^(@)` and `97^(@)` respectively (`H_(t)=` terminal hydrogen atoms, `H_(b)` = BRIDGED hydrogen atoms).

Discussion

2.	In differential extraction from two layer……layer is above because……
Answer» SOLUTION :SOLVENT, its DENSITY is LESS

Discussion

3.	In diborane, the number of electronsthat account for bondingin the bridges is
Answer» SIX TWO eight four Solution :There are fourelectronsin two BRIDGES.

Discussion

4.	In diborane, the hybridisation of Boron is
Answer» SP `sp^2` `sp^3` `sp^3 d` ANSWER :C

Discussion

5.	In diborane , the number of electrons that account for bonding in the bridges is
Answer» six two eight four Solution :DIBORANE has two 3c-2e BONDS (bridges). Thus there are 4 ELECTRONS for bonding in the bridges.

Discussion

6.	In diamond lattice, all lattice points and alternate tetrahedral voids are occupied by carbon atoms. If diamond crystallizes in fcc form with edge length 'a' , find out (a)number of next nearest neighbours in diamond lattice (b)distance between the next nearest neighbours.
Answer» Solution :(a)Nearest neighbours are atoms at the LATTICE POINS and tetrahedral voids. Hence, NEXT nearest neighbours are atoms at the lattice POINTS. `therefore` Number of next nearest neighbours =12 (being fcc lattice ) (B) For fcc, nearest neighbour distance (d)=`a/sqrt2`=0.707 a

Discussion

7.	In diborane, banana bond is formed between
Answer» 2 ELECTRONS, 3 ATOMS 2 electrons, 1 atom 2 electrons, 2 atoms 1 ELECTRON, 2 atoms. Solution : 2 electrons, 3 atoms

Discussion

8.	In diammonium phosphate (NH_(4))_(2)HPO_(4), the percentage of P_(2)O_(5) is
Answer» <P>`35.87` `46.44` `51.99` `53.78` Solution :`%P_(2)O_(5)=(142)/(2xx132)XX100`

Discussion

9.	In determination by Victor Meyer method, 0.60 g of a volatile substance expelled 123 mL of air measured over water at 20^(@)C and 757.4 mm pressure. Find the molecular mass of the substance. Aqueous tension at 20^(@)C is 17.4 mm.
Answer» SOLUTION :MASS of the organic substance `=0.60 g` Volume of the displaced air `=123.0 mL` Temperature at which air is collected `=20^(@)C=(20+273)=293 K` Pressure at which air is collected `=757.4 mm` Aqueous tension at `293 K=17.4 mm` Pressure of the dry air `=757.4-17.4=740 mm` STEP I. Calculationof the volume of the air displaced (or vapours of the substance) at N.T.P. `{:("EXPERIMENTAL conditions","N.T.P. conditions"),(V_(1)=123.0 mL,V_(2)=?),(P_(1)=740 mm,P_(2)=760 mm),(T_(1)=293 K,T_(2)=273 K):}` By applying gas equation : `(P_(1)V_(1))/T_(1)=(P_(2)V_(2))/T_(2)` or `V_(2)=(P_(1)V_(1)T_(2))/(T_(1)P_(2))=((740mm)xx(123.0 mL)xx(273 K))/((293K)xx(760 mm))=111.6 mL` Step II. Calculation of the molecular mass. 111.6 mL of vapours are obtained from subtance = 0.60 g 22400 mL of vapours are obtained from substance `=((0.60g)xx(22400 mL))/((111.6 mL))=120.4 g` `:.` Molecular mass of the substance `=120.4 g mol^(-1)`.

Discussion

10.	In detection of halogen what is form by adding AgNO_(3) ? What is its colour?
Answer» Solution :(i) Precipitate of AGX (ii) WHITE precipitate of AGCL (iii) LIGHT yellow precipitate of AgBr (IV) Yellow precipitate of AgI

Discussion

11.	In dehydrohalogenation, hydrogen and halogen are removed from
Answer» the same CARBON atom adjacent carbon atoms isolate carbon atoms any TWO carbon atoms Answer :B

Discussion

12.	In dehalogenation reaction of dihalides to get alkenes, the dihalide to be taken is
Answer» Gem dihalide Vicinal dihalide ISOLATED dihalide Any dihalide Answer :B

Discussion

13.	In CuSO_4.5H_2Oall Cu- O bond length are not equal. The total number of shorter Cu - O bonds will be
Answer» 4 1 2 3 Answer :A

Discussion

14.	In curing cement plasters , water is sprinkled from time to time . This helps in
Answer» converting sand into silicic acid keeping it COOL developing interlocking needle LIKE crystals of HYDRATED SILICATES hydrating sand and gravel mixed with cement Answer :C

Discussion

15.	In curing cement plasters, water is sprinkled from time to time. This helps in....
Answer» converting sand into silica acid. KEEPING it cool. developing interlocking needle like CRYSTALS of HYDRATED silicates. hydrating sand and GRAVEL mixed with cement. Answer :C

Discussion

16.	In curing cement plasters, water is sprinkled from time to time. Which of the following statements are incorrect.
Answer» keeping it cool converting SAND in to silicic acid HYDRATED sand gravel mixed with cement developing interlocking NEDDLE like CRYSTALS of hydrated silicates Solution :The three resons are not correct. Reason : developing interlocking needle like cyrstals of hydrated silicates.

Discussion

17.	In Cu - Zn cell
Answer» Reduction occurs at the copper cathode Oxidation occurs at the copper cathode Reduction occurs at the anode Chemical energy is converted to LIGHT energy SOLUTION :In Cu-Zu CELL copper ACTS a cathode . So, reduction takes place at copper cathode.

Discussion

18.	In Cu (At. No. 29)
Answer» 13 ELECTRONS have SPIN in one direction and 16 electrons in other direction 14 electrons have spin in one direction and 15 electrons in other direction one electron can have spin only in the clockwise direction none of the above is correct. Solution :`._(29)Cu = [Ar[^(18) 3D^(10) 4s^(1)` All electrons are paired except `4s^(1)`. Hence, `14E^(-)` have spin one direction and `15 e^(-)` in the other

Discussion

19.	In crystals of which of thefollowingionic compounds wouldyou expect themaximum distancebetweencentres ofcationsand anions
Answer» `CsF` `CsI` `LII` `LIF` Solution :Bigger the SIZEOF ions `(CS^(+)` and`I^(-))` longer is thedistancebetweenthe CENTRES oftheirnuclei

Discussion

20.	In CsCl, if the co-ordination number of Cs^(+) is 8 then co-ordination number of Cl^(-) ion is
Answer» 8 16 6 4 Answer :A

Discussion

21.	In crystal structure of NaCl, total number of Cl^- ions in a unit cell is
Answer» 6 4 8 2 Answer :B

Discussion

22.	In crystal structure ofNaCl, total number ofCl^(-)ionsin a unit cell is
Answer» 6 4 8 2 Answer :B

Discussion

23.	In covalent bond
Answer» TRANSFER of electrons takes place sharing of electrons takes place electrons are SHARED by only ONE atom none of these Answer :B

Discussion

24.	In corundum, oxide ions are arranged in hexagonal close packing and aluminium ions occupy two-third of the octahedral voids. What is the formula of corundum ?
Answer» SOLUTION :Suppose oxide ions =n. Then octahedral voids= n. HENCE, `Al^(3+)` ions `=2/3xxn="2n"/3` `therefore` Ratio `Al^(3+) : O^(2-)="2n"/3:n =2:3` , i.e., FORMULA is `Al_2O_3`

Discussion

25.	In corrundum, oxide ions are arranged in hexagonal close packing and aluminium ions occupy two-third of the octahedral voids. What is the formula fo corrundum ?
Answer» SOLUTION : SUPPOSE oxideions = n . Then octahedral voids = n Hence,` Al^(3+) " ions"= 2/3 xx n = (2n)/3` RATIO` Al^(3+): O^(2-)= (2n)/ 3 : n = 2: 3`FORMULA is ` Al_(2)O_(3)` \

Discussion

26.	In correct statement about the structure of PCl_5
Answer» AXIAL P - CL BONDS have more bondlength than equtorial P -Cl bonds `d_z^2` orbital is involved in `Sp^3d` hybridization. The no. of planar ATOMS in `PCl_5` is 4 Phosphorous is in 2nd EXCITED state. Answer :D

Discussion

27.	In conversion of limestone to lime, CaCO_(3)(s) to CaO(s) + CO_(2)(g) the values of DeltaH^(@) and DeltaS^(@) are + 179.1 kJ mol^(-1) and 160.2 J/K respectively at 298 K and 1 bar. Assuming that DeltaH^(@) and DeltaS^(@) do not change with temperature, the temperature above which conversion of limestone to lime will be spontaneous is:
Answer» 1200 K 845 K 1118 K 1008 K Solution :`T = (DeltaH^(@))/(DELTAS^(@)) = (179.1 xx 10^(3)J)/(160.0JK^(-1))` ` = 1117.97 = 1118 K`

Discussion

28.	In contrast with beryllium, which one of the following statements is incorrect -
Answer» it forms `Be_2C` its salts rarely hydrolysed its hydride is electron DEFICIENT and polymeric it is rendered passive by nitric ACID Solution :Beryllium forms covalent compounds, thus HYDROLYSIS of beryllium compounds occurs readily.

Discussion

29.	In context with the industrial preparation of hydrogen from water gas (CO+H_(2)), which of the following is the correct statement ?
Answer» CO is oxidising to `CO_(2)` with STEAM in the presence of a catalyst followed by absorption of `CO_(2)` in alkali `CO and H_(2)` are fractionally separated USING DIFFERENCES in their densities CO is REMOVED by absorption in aqueous `Cu_(2)Cl_(2)` solution `H_(2)` is removed through occlusion with Pd Answer :A

Discussion

30.	In context with the industrial preparation of hydrogen from water gas (CO + H_2), which of the following is the correct statement ?
Answer» CO is removed by absorption in aqueous `CaCl_2` solution. `H_2` is removed through occlusion with PD CO is oxidised to `CO_2` with steam in the PRESENCE of a catalyst followed by absorption of `CO_2` in ALKLI. CO and `H_2` are fractionally SEPARATED USING differences in their densities. Answer :C

Discussion

31.	Which of the following statement is correct?
Answer» CO and `H_2` are fractionally separated using differences in their densities CO is removed by ABSORPTION in AQUEOUS `Cu_2Cl_2` is solution `H_2` is removed through occlusion with Pd CO is oxidised to `CO_2` with steam in the presence of a CATALYST followed by absorption of `CO_2` in alkali Solution :`underset("steam")(CO + H_2O to CO_2 + H_2)`

Discussion

32.	In context with beryllium , which one of the following statements is incorrect ?
Answer» It is rendered passive by nitric acid It FORMS `Be_(2)C` Its SALTS rarely hydrolyze Its hydride is electron-deficient and polymeric . Solution :DUE to small size and HIGH hydration enthalpy Be COMPOUNDS readily hydrolyse .

Discussion

33.	In context with beryllium, which one of the following statements is incorrect?
Answer» It is RENDERED PASSIVE by nitric acid It forms `Be_2C` Its SALTS are rarely hydrolysed Its hydride is electron deficient and polymeric Answer :C

Discussion

34.	In compounds of type ECl_3, where E = B, P, As or Bi, the angles CI-E - CI for different E are in the order
Answer» <P>`B gtP= As = Bi ` ` B gtP gtAsgtBi` `BLT P = As = Bi ` `Blt P LT As LTBI ` Answer :B

Discussion

35.	In the compound 'X', all the bond angles are exactly 109^(@)28. 'X' may be________.
Answer» CHLOROMETHANE IODOFORM CARBON TETRACHLORIDE chloroform Answer :C

Discussion

36.	In compound A, 1.00 g nitrogen unites with 0.57 g oxygen. In compound B, 2.00g nitrogen combines with 2.28 g oxygen. In compound C, 3.00 g nitrogen combines with 5.13 g oxygen. These results obey the following law.
Answer» Law of constant PROPORTION Law of multiple proportion Law of reciprocal proportion Dalton.s law of partial pressure Solution :`{:(,N_(2),O_(2)),("A",1gm,0.57g),("B",2gm,2.24g),(,1gm,1.12g),("C",3gm,5.11g),(,1gm,1.7g):}` implies different COMPOUNDS.

Discussion

37.	Incomplete combustion of petrol in automobile engines can be detected by testing the fuel gases for the presence of
Answer» `NO_(2)` CO `CO_(2)` `CO+ H_(2)O` SOLUTION :TESTING the fuel GASES in the PRESENCE of .CO.

Discussion

38.	In comparison to the zeolite process for the removal of permanent hardness, the synthetic resins method is:
Answer» LESS EFFICIENT as it exchanges only anions. More efficient as it can exchanges only cations. Less efficient as the RESINS cannot be generated. More efficient as it can exchange both cations and anions. Answer :D

Discussion

39.	In comparison to boron, berylium has :
Answer» (A) LESSER nuclear charge and greater FIRST IONISATION enthalpy (B) greater nuclear charge and greater first ionisation enthalpy (C) greater nuclear charge and lesser first ionisation enthalpy (D) lesser nuclear charge and lesser first ionisation ethalpy. Solution : lesser nuclear charge and greater first ionisation enthalpy

Discussion

40.	In commercial electrochemical process for Al extraction, electrolyte used is
Answer» `AL(OH)_(3)` in `NAOH` SOLUTION An aqueous solution of `Al_(2)(SO_(4))_(3)` A molten MIXTURE of `Al_(2)O_(3)` and `Na_(3)AlF_(6)` A molten mixture of `Al(OH)_(3)` and `AlO(OH)` Solution :Al is extracted commercially by the electrolysis of a molten mixture of `Al_(2)O_(3)` (ALUMINA) and `Na_(2)AlF_(6)` (cryolite).

Discussion

41.	In commerical reverse osmosis process, the semi permeable membrane used is …………………..
Answer» SOLUTION :CELLULOSE ACETATE

Discussion

42.	In commercial electro chemical process for Al extraction electrolyte used as
Answer» `AL(OH)_(3)` in NaOH SOLUTION aq. `Al_(2)(SO_(4))_(3)` Al MOLTEN mixture of `Al_(2)O_(3)` and `Na_(3)AlF_(6)` none of the above Solution :Only .NaOH. because it is basic in nature.

Discussion

43.	In column chromatography the moving phase consists
Answer» A SUBSTANCE which is to be separated Mixture of ELUENT and adsorbent Eluent Adsorbent Answer :C

Discussion

44.	In column chromatography stationary, phase is
Answer» Only SOLID Only LIQUID Only GAS All of these ANSWER :A

Discussion

45.	In close vessel the reaction A_((s)) hArr 4B_((g)) + 3C_((g))is in equilibrium. If the partial pressure of C is double then what will be the partial pressure of B?
Answer» SOLUTION :`1/(2SQRT2)` TIMES of ESSENTIAL PRESSURE

Discussion

46.	In close vessel at 298 K temperature, the water vapour pressure is 25 mm. Then which equilibrium is it ?
Answer» HOMOGENEOUS EQUILIBRIUM Hetrogeneous equilibrium Chemical equilibrium IONIC equilibrium Answer :B

Discussion

47.	In Clark's method, the obstance used for the removal of temporary hands of Willer
Answer» `NaOH` `CaCO_3` `Ca(OH)_2` `Ca(HCO_3)_2` ANSWER :C

Discussion

48.	In Cl_(2) molecule covalent radius is 99 pm and van-dar-Walls radius is 180 pm what is the distance between two nucleus and distance between two molecules ?
Answer» <P> SOLUTION :198 PM and 360 p respectvely

Discussion

49.	In cis and trans, whose dipole moment is more, explain with example ?
Answer» Solution :`CH_(3)CH=CHCH_(3)` has 2 geometrical isomers : (i) Cis-but-2-ene (ii) Trans-but-2-ene. Always cis-isomer DIPOLE moment `(mu) gt` Trans-isomers. Isomers of But-2-ene are shown with its isomers and dipole moment. Trans-but-2-ene has `2-CH_(3)` group, they are in opposite side therefore dipole moments of `C-CH_(3)` BONDS circle, thus making the trans form non-polar. Cis isomers are polar because in Cis-but-2-ene has `2-CH_(3)` group and they are on same side of double bond. ELECTRONEGATIVITY of `C_CH_(3)` are added, in which the dipole moment is more. therefore, cis-isomer is polar and trans isomer is non-polar.

Discussion

50.	In CIF_(3),NF_(3)andBF_(3) molecules the chlorine nitrogen and boron atoms are…
Answer» `SP^(3)` hybridised `sp^(3),sp^(3), and sp^(3)` respectivily `sp^(2)` hybridised `sp^(3)d,sp^(3)and sp^(2)` hybridiesd respectively Answer :D

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In diborane the two H-B-H angles are nearly

In differential extraction from two layer……layer is above because……

In diborane, the number of electronsthat account for bondingin the bridges is

In diborane, the hybridisation of Boron is

In diborane , the number of electrons that account for bonding in the bridges is

In diamond lattice, all lattice points and alternate tetrahedral voids are occupied by carbon atoms. If diamond crystallizes in fcc form with edge length 'a' , find out (a)number of next nearest neighbours in diamond lattice (b)distance between the next nearest neighbours.

In diborane, banana bond is formed between

In diammonium phosphate (NH_(4))_(2)HPO_(4), the percentage of P_(2)O_(5) is

In determination by Victor Meyer method, 0.60 g of a volatile substance expelled 123 mL of air measured over water at 20^(@)C and 757.4 mm pressure. Find the molecular mass of the substance. Aqueous tension at 20^(@)C is 17.4 mm.

In detection of halogen what is form by adding AgNO_(3) ? What is its colour?

In dehydrohalogenation, hydrogen and halogen are removed from

In dehalogenation reaction of dihalides to get alkenes, the dihalide to be taken is

In CuSO_4.5H_2Oall Cu- O bond length are not equal. The total number of shorter Cu - O bonds will be

In curing cement plasters , water is sprinkled from time to time . This helps in

In curing cement plasters, water is sprinkled from time to time. This helps in....

In curing cement plasters, water is sprinkled from time to time. Which of the following statements are incorrect.

In Cu - Zn cell

In Cu (At. No. 29)

In crystals of which of thefollowingionic compounds wouldyou expect themaximum distancebetweencentres ofcationsand anions

In CsCl, if the co-ordination number of Cs^(+) is 8 then co-ordination number of Cl^(-) ion is

In crystal structure of NaCl, total number of Cl^- ions in a unit cell is

In crystal structure ofNaCl, total number ofCl^(-)ionsin a unit cell is

In covalent bond

In corundum, oxide ions are arranged in hexagonal close packing and aluminium ions occupy two-third of the octahedral voids. What is the formula of corundum ?

In corrundum, oxide ions are arranged in hexagonal close packing and aluminium ions occupy two-third of the octahedral voids. What is the formula fo corrundum ?

In correct statement about the structure of PCl_5

In contrast with beryllium, which one of the following statements is incorrect -

In context with the industrial preparation of hydrogen from water gas (CO+H_(2)), which of the following is the correct statement ?

In context with the industrial preparation of hydrogen from water gas (CO + H_2), which of the following is the correct statement ?

Which of the following statement is correct?

In context with beryllium , which one of the following statements is incorrect ?

In context with beryllium, which one of the following statements is incorrect?

In compounds of type ECl_3, where E = B, P, As or Bi, the angles CI-E - CI for different E are in the order

In the compound 'X', all the bond angles are exactly 109^(@)28. 'X' may be________.

In compound A, 1.00 g nitrogen unites with 0.57 g oxygen. In compound B, 2.00g nitrogen combines with 2.28 g oxygen. In compound C, 3.00 g nitrogen combines with 5.13 g oxygen. These results obey the following law.

Incomplete combustion of petrol in automobile engines can be detected by testing the fuel gases for the presence of

In comparison to the zeolite process for the removal of permanent hardness, the synthetic resins method is:

In comparison to boron, berylium has :

In commercial electrochemical process for Al extraction, electrolyte used is

In commerical reverse osmosis process, the semi permeable membrane used is …………………..

In commercial electro chemical process for Al extraction electrolyte used as

In column chromatography the moving phase consists

In column chromatography stationary, phase is

In close vessel the reaction A_((s)) hArr 4B_((g)) + 3C_((g))is in equilibrium. If the partial pressure of C is double then what will be the partial pressure of B?

In close vessel at 298 K temperature, the water vapour pressure is 25 mm. Then which equilibrium is it ?

In Clark's method, the obstance used for the removal of temporary hands of Willer

In Cl_(2) molecule covalent radius is 99 pm and van-dar-Walls radius is 180 pm what is the distance between two nucleus and distance between two molecules ?

In cis and trans, whose dipole moment is more, explain with example ?

In CIF_(3),NF_(3)andBF_(3) molecules the chlorine nitrogen and boron atoms are…