52671 + Interview Questions in Chemistry in Class 11

1.	The molecules BF_3 and NF_3are covalent compounds. But BF_3is non-polar and NF_3is polar. The reason is
Answer» Boron is a metal and nitrogen is a gas in uncombined state BF BONDS have no DIPOLE moment where as NF bonds have dipole moment Atomic size of boron is SMALLER that that of nitrogen `BF_3 ` is planar but `NF_3` is PYRAMIDAL in shape Answer :D

Discussion

2.	The molecule with maximum number of lone pairs on central atom is
Answer» `XeO_3` `SF_4` `PCl_5` `1Cl_3` ANSWER :D

Discussion

3.	The molecule which contains sigma_(sp^3-sp^3) and sigma_(sp^3-p) bonds in it is
Answer» `CH_3 CH_3` `CH_3CHO` `CH_3CH_2Cl` `CH Cl_3` SOLUTION :C - C BOND is `SP^3-SP^3` and C - CL is `SP^3-P`

Discussion

4.	The molecule orbital shown in the diagram can be described as
Answer» `SIGMA` `simga` `PI` `pi` ANSWER :D

Discussion

5.	The molecule in which the distance between the two adjacent carbon atom is largest in…..
Answer» ethane ethene ethyne benzene Answer :A

Discussion

6.	Molecule with zero dipole moment is
Answer» `CHCl_3` `CH_2 Cl_2` `C Cl_4` `CH_3 CL` ANSWER :C

Discussion

7.	The molecule having smallest bond angle is
Answer» `AsCl_(3)` `SbCl_(3)` `PCl_(3)` `NCl_(3)` SOLUTION :`SbCl_(3)` As we move down the group the size of atom increases and as size of central atom increases, lone pair-bond pair repulsion also increases. Thus bond angle decreases. Increasing order of ATOMIC radius : `N lt P lt As lt Sb ` Decreasing order of bond angle : `NCl_(3) GT PCl_(3) gt AsCl_(3) gt SbCl_(3)`

Discussion

8.	The molecule havaing smallest bond angle is
Answer» `AsCI_(3)` `SbCl_(3)` `PCl_(3)` `NCl_(3)` Solution :`SbCl_(3)` has the smallest bond ANGLE because amongst N,P, As and Sb,Sb has the LOWEST electronegativity.

Discussion

9.	The molecule has...........structure
Answer» ANSWER :TETRAHEDRAL

Discussion

10.	The molecule H_(3)C-CH=CH-underset(CH_(3))underset(\|)CH-COOH can exhibit
Answer» Geomelical isomeronly Optical ISOMERISM only Conformational and optical isomerism Tautomerism Solution :DUE to UNSATURATION and chiral CARBON

Discussion

11.	The molecule H_3C - CH = CH - underetoverset(\|)(CH_3)(C )H - COOHcan exhibit
Answer» GEOMETRICAL ISOMERISM only Optical isomerism only Conformational and optical isomerism Tautomerism Solution : Due to unsaturation and chiral CARBON

Discussion

12.	The molecular weights of two ideal gases A and B are respectively 100 and 200. One gram of A occupies V litres of volume at STP. What is the volume (in litres) occupied by one gram of B at STP ?
Answer» V/2 V 4 V 2V SOLUTION :Moles `PROP` volume

Discussion

13.	The molecular weight of low density polythene ranges between .......and.....
Answer» SOLUTION :50,000, 3,00,000

Discussion

14.	The molecular weight of haemoglobin is about 65.000 g/mol. Haemoglobin contains 0.35% Fe by mass. How many iron atoms are there in a haemoglobin molecule?
Answer» Solution :100 g of haemoglobin contain 0.35 g of IRON. or, `100/65000` mole of haemoglobin CONTAINS `0.35/56` mole of Fe. `THEREFORE 1` mole of haemoglobin contains `0.35/56 xx 65000/100` MOLES of Fe. =4.06 moles of Fe Thus, one molecules of haemoglobin contains four iron atoms.

Discussion

15.	The molecular weight of benzoic acid in benzene as determined by depression in freezing point method correcponds to
Answer» IONIZATION of benzoic ACID Dimerizaton of benzoic acid Trimerization of benzoic acid Solution of benzoic acid Solution :Benzaoic acid EXISTS as a DIMER in benzene

Discussion

16.	The molecular weight of an organic compound is 180. Its empirical formula is CH_(2)O. Its molecular formula is
Answer» `CP_(6)H_(12)O_(6)` `C_(7)H_(16)O_(5)` `C_(8)H_(4)O_(5)` `C_(5)H_(8)O_(7)` Answer :A

Discussion

17.	The Molecular weight of a gas is 40. At 400K if 120 g of this gas has a volume of 20 litres, the pressure of the gas in atm is
Answer» `4.92` `5.02` `49.6` `0.546` ANSWER :A

Discussion

18.	The molecular velocity of any gas is
Answer» inversely PROPORTIONAL to the SQUARE ROOT of temperature inversely proportional to absolute temperature directly proportional to square of temperature directly proportional to square root of temperature. Solution :directly proportional to square root of temperature.

Discussion

19.	The molecular speeds of gasesous molecules are analogous to those of rifle bullets. Then why is the odour of a gas not detected so fast ?
Answer» Solution :Though the molecules of a gas travel at HIGH speeds but they do not travel in straight lines in one direction like bullets. As they travel, they collide with the molecules of the gases PRESENT in the air. As a result, they are deflected. Thus, they follow a zig-zag PATH, i.e., the net distance travelled in a PARTICULAR direction is quite small in a given TIME. That is why the odour is not detected so fast.

Discussion

20.	The molecular orbital electronic configuration is (sigma_(1s))^(2),(sigma_(1s)^(**))^(1). It corresponding to
Answer» `He_2` `He_(2)^(+)` `H_(2)^(-)` BOTH2 & 3 Answer :D

Discussion

21.	The molecular orbital shown below is described as
Answer» `sigma^()` `sigma` `PI` NON bonding. Solution :It is for s-p OVERLAP `sigma^()` ORBITAL for a HETERO -atomicmolecule.

Discussion

22.	The molecular mass of Mohr's salt, FeSO_(4)(NH_(4))_(2)SO_(4). 6H_(2)O, is 392. Its equivalent mass is :
Answer» 196 39.2 `98.0` 392 Solution :N//A

Discussion

23.	The molecular mass of K_(2)Cr_(2)O_(7) is 294 amu. It acts as oxidising agent in a redox titration. Its equivalent mass in acid medium will be :
Answer» 294 49 147 74 Solution :`K_(2)overset(+12)(Cr_(2))O_(7)+4H_(2)SO_(4)to K_(2)SO_(4)+overset(+6)(Cr_(2)(SO_+(4))_(3)+4H_(2)O+3[O]` Change in oxidation number = 6 EQUIVALENT mass `=("Molecular mass")/(6)=(294)/(6)=49`

Discussion

24.	The molecular mass of H_(3)PO_(3) is 82. Its equivalent mass, if it is completely neutralised, is:
Answer» 82 27.3 41 246 Solution :N//A

Discussion

25.	The molecular mass of KMnO_(4) is M.Its equivalent mass in acidic medium will be :
Answer» M `M//2` `M//5` `M//4` SOLUTION :N//A

Discussion

26.	The molecular mass of hydrogen peroxide is 34. What is the unit of molecular mass ?
Answer» mole g kg /mole g /mole Answer :D

Discussion

27.	The molecular mass of benzene is 78 amu. Its percentage composition is 92.31 % C and 7.69 % H. Determine the molecular formula of benzene.
Answer» SOLUTION :Step I. Empirical formula of benzene `{:("Element","Percentage","Atomic mass","Gram ATOMS (Moles)","Atomic ratio (Molar ratio)","Simplest WHOLE no. ratio"),("C",92.31,12,(93.31)/(12)=7.69,(7.69)/(7.69)=1,1),("H",7.69,1,(7.69)/(1)=7.69,(7.69)/(7.69)=1,1):}` Empirical formula of benzene = CH Step II. Molecular formula of benzene Empirical formula mass `= 12 +1 =13u` Molecular mass `= 78 u` `N=("Molecular mass")/("Empirical formula mass")=((78u))/((13u))=6` Molecular formula `= n xx` Empirical formula `=6xx CH = C_(6)H_(6)`.

Discussion

28.	The molecular mass of an organic acid was determined by the study of its barium salt. 4.290g of salt was quantitiatively converted to free acid by the reaction with 21.64ml of 0.477 MH_(2)SO_(4). The barium salt was found to have two moles of water of hydration per Ba^(+2) ion and the acid is mono basic. what is molecular weight of anhydrous acid.
Answer» `137.32` `415.7` `242.4` `244.4` Solution :MEQ of barium salt = Meq. of acid `=21.64 xx 0.477 xx 2 = 20.64` Molecular weight of salt `=415.7` MW of ANHYDROUS salt `=379.7` Molecular weight of anion `=397.7 - 137.3 = 242.4` Molecular weight of acid `= 244.4`

Discussion

29.	The molecular mass of an organic acid was determined by the study of its barium salt. 4.290 g of salt was quantitatively converted to free acid by the reaction with 21.64 mL of 0.477 M H_(2)SO_(4). The barium salt was found to have two mole of water of hydration per Ba^(2+) ion and the acid is mono-basic. What is molecular weight of anhydrous acid?
Answer» ANSWER :`122.31`;

Discussion

30.	The molecular mass of an organic acid was determind by the study of its barium salt. 4.290 g of salt was converted to free acid by the reaction with 21.64 mL of water of hydration per Ba^(2+) ion and the acid is monobasic. What is molecular weight of anhydrous acidgt
Answer» Solution :MEQ of Braium SALT = mEq of acid `(4.290)/(Mw..2) XX 1000 = 21.64 xx 0.477 xx 2` MOLECULAR weight of salf = 415.60 Molecular weight of anion `= (("Mw of salt" - Mw of BA^(2+) - Mw of 2 H_(2) O))/(2)` `= (415.60 - 137 - 36)/(2) = 121.16` `:.` Molecular weight of acid `= 121.6 + 1 = 122.6`

Discussion

31.	The molecular interaction responsible for hydrogen bonding in HF.
Answer» ion-induced DIPOLE dipole-dipole ion-dipole dipole-induced dipole Answer :B

Discussion

32.	The molecular formular of a commerical resin used for exchanging ions in water softening is C_(8)H_(7)SO_(3)Na(Mol . Wt. of 206). What would be the maximum uptake of Ca^(2+) ions by the resin when expressed in mole per gram resin ?
Answer» `2//3009` `1//412` `1//103` `1//206` Solution :`UNDERSET(2xx206=412 g)underset(2 "mol")(2C_(8)H_(7)SO_(3)^(-)Na^(+)) + underset("1 mol")(Ca^(2+)) to ` `(C_(8)H_(7)SO_(3)^(-))_(2)Ca^(2+)+Na^(+)` `therefore ` 1 mole of `Ca^(2+)=412` g of resin or maximum uptake of `Ca^(2+)` ions by the resin `=(1 mol)/(412g)=(1)/(412) ` mol/g

Discussion

33.	The molecular formula of the compound formed from B and C will be :
Answer» BC `B_(2)C` `BC_(2)` `BC_(3)` Solution :The molecular FORMULA will be `BC_(3).` The compound is `PCl_(3)`

Discussion

34.	The molecular formula of Napthacene is ……..
Answer» `C_(18)H_(10)` `C_(18)H_(12)` `C_(14)H_(28)` `C_(18)H_(14)` Answer :B

Discussion

35.	The molecular formula of Iron (III) Sulphate is ____ .
Answer» `Fe_(3)(SO_(4))_(2)` `Fe_(3)SO_(4)` `FeSO_(4)` `Fe_(2)(SO_(4))_(3)` Solution :`SO_(4)^(2-)ANDFE^(III)` are (-) ve and positive ions. They can FORM the neutral compound `Fe_(2)(SO_(4))_(3)`

Discussion

36.	The molecular formula of inorganic benzene is "………….." and is obtained by heating the adduct of "………….." with "…………..".
Answer» Answer :`B_(3)N_(3)H_(6), B_(2), H_(6), NH_(3)`

Discussion

37.	The molecular formula of an organic compound is C_(4)H_(9)N. The volume of N_(2) that will be given by 0.2 g of the above compound at STP is …….. (ml)
Answer» 31.5 50 63 93 Solution :M.wt PF `C_(4)H_(9)N = 71` 71 grams LIBERATE 11,200 ml `N_(2)` 0.2 gram liberate …….. ? …….. `N_(2)`

Discussion

38.	The molecular formula of an organic compound is C_(4)H_(9)N. The volume of N_(2) that will be given by 0.2g of the above compound at STP is…(ml)
Answer» 31.5 50 63 93 Answer :A

Discussion

39.	The molecular formula of a commercial resin used for exchanging ions in wter softening is C_(8)H_(7)SO_(3Na (mol.wt.206), What would be the maximum uptake of Ca^(2+) ions by resin when expressed in moe per gram resin?
Answer» `(2)/(309)` `(1)/(412)` `(1)/(103)` `(1)/(206)` Solution :(b) `UNDERSET(2xx206=412g)underset(2"mol")(2C_(8)H_(7)SO_(3)^(-)Na^(+))+underset(1"mol")(CA^(2+)) to (2C_(8)H_(7)SO_(3)^(-))_(2)Ca^(2+)+2Na^(+)` `"1 mole of" Ca^(2+)=412"g of RESIN"` `"Maximum uptake of" Ca^(2+) "ions by the resin" =(1"mol")/(412g)`

Discussion

40.	The molecular fo rmula of the compound formed from 8 and C will be
Answer» BC `B_(2)C` `BC_(2)` `BC_(3)` Solution :`BC_(3)` In the electronic CONFIGURATION SHOW that B represents PHOSPHORUS and C represents chlorine. The stable compound formed is `PCl_(3)`i.e., `BC_(3)`

Discussion

41.	The molecule electronic configuration of B_(2) is
Answer» `KK ( SIGMA 2s)^2 ( sigma^()2s)^2 ( PI 2p)_(x)^(1) ( PIP)_(y)^(1)` `KK ( sigma 2s)^2 ( sigma^()2s)^2 ( pi 2p)_(x)^(2) ` `KK ( sigma 2s)^2 ( sigma^()2s)^2 ( pi 2p)^2` `KK ( sigma 2s)^2 ( sigma^()2s)^2 ( pi 2p)^(1) ( pip)^(1)` ANSWER :A

Discussion

42.	The mole ratio of products H_(2), NaOH, CI_(2) formed in a Nelson cell method is
Answer» `1:2:1` `2:2:1` `1:1:2` `1:1:1` ANSWER :A

Discussion

43.	What is the mole percentage of O_(2) in a mixture of 7g of N_(2) and 8g of O_(2)?
Answer» 25% 72% 50% 40% ANSWER :C

Discussion

44.	The mole fraction of water in a solution of HCI is 0.78. Calculate the molality of the solution.
Answer» SOLUTION :Mole fraction of WATER = 0.78 Mole fraction of HCI = `1 - 0.78 = 0.22`. SUPPOSE, the solution contains `n_(1)`moles of HCI and `n_2` moles of water. Therefore, `n_(1)/(n_(1) + n_(2)) = 0.22`……..(i) and `n_(2)/(n_(1) + n_(2)) = 0.78`……...........(ii) DIVIDING eq. (i) by eq. (ii), we have `n_(1)/n_(2) = 0.22/0.78 = 0.28`.............(iii) Since, molality refers to the number of moles of solute dissolved in 1000 g of solvent (water in the present case), `n_(2) = 1000/18 = 55.55` Substituting the value in eq. (iii), we have `n_(1)/55.55 =0.28` or `n_(1) = 0.28 xx 55.55 = 15.55` Hence, the molality of the given solution is 15.55 m.

Discussion

45.	The mole fraction of solute in an aqueous solution is (1)/(112). The molality (m) of the solution is 0.1x. What is x?
Answer» Solution :`(X_(1))/(X_(2))=(mM_(2))/(1000)IMPLIES(1//112)/(111//112)=(mxx18)/(1000)impliesm=0.5`

Discussion

46.	The mole fraction of benzene in a solution in toluene is 0.40. Calculate the weight per cent of benzene in the solution.
Answer» ANSWER :35.88

Discussion

47.	The mole concept helps in handling a large number of atoms and molecules in stoichiometric calculations. Calculate the amount of CO_2 formed by the complete combustion of 80 g of methane as per the reaction CH_(4(g))+2O_(2(g))rarrCO_(2(g))2H_2O_((g)) (Atomic masses: C = 12.01u, H = 1.008u, O=16u)..
Answer» SOLUTION :`CH_(4g)+2O_2toCO_2+2H_2O16g` of `CH_4` GIVEN 44 G of `CO_2`

Discussion

48.	What is the number of hydrogen atoms in one mole of methane (CH_4)?
Answer» Solution :Number of HYDROGEN ATOMS =No. of mole `xxN_Axxn=4N_A=1xx6.023xx10^23xx10^24xx4=24.092xx10^23"atoms"=2.409xx10^24`ATOM

Discussion

49.	Define 1 mole
Answer» Solution :1 MOLE is defined as the AMOUNT of any substance which contains one Avogadro NUMBER of particles. (i.e” atoms, ions or molecules)

Discussion

50.	The molarity of the solution containing 2.8%(mass/volume) solution of KOH is : (Given atomic mass of K = 39)
Answer» `0.1` M `0.5` M `0.2` M 1 M Answer :B

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The molecules BF_3 and NF_3are covalent compounds. But BF_3is non-polar and NF_3is polar. The reason is

The molecule with maximum number of lone pairs on central atom is

The molecule which contains sigma_(sp^3-sp^3) and sigma_(sp^3-p) bonds in it is

The molecule orbital shown in the diagram can be described as

The molecule in which the distance between the two adjacent carbon atom is largest in…..

Molecule with zero dipole moment is

The molecule having smallest bond angle is

The molecule havaing smallest bond angle is

The molecule has...........structure

The molecule H_(3)C-CH=CH-underset(CH_(3))underset(|)CH-COOH can exhibit

The molecule H_3C - CH = CH - underetoverset(|)(CH_3)(C )H - COOHcan exhibit

The molecular weights of two ideal gases A and B are respectively 100 and 200. One gram of A occupies V litres of volume at STP. What is the volume (in litres) occupied by one gram of B at STP ?

The molecular weight of low density polythene ranges between .......and.....

The molecular weight of haemoglobin is about 65.000 g/mol. Haemoglobin contains 0.35% Fe by mass. How many iron atoms are there in a haemoglobin molecule?

The molecular weight of benzoic acid in benzene as determined by depression in freezing point method correcponds to

The molecular weight of an organic compound is 180. Its empirical formula is CH_(2)O. Its molecular formula is

The Molecular weight of a gas is 40. At 400K if 120 g of this gas has a volume of 20 litres, the pressure of the gas in atm is

The molecular velocity of any gas is

The molecular speeds of gasesous molecules are analogous to those of rifle bullets. Then why is the odour of a gas not detected so fast ?

The molecular orbital electronic configuration is (sigma_(1s))^(2),(sigma_(1s)^(**))^(1). It corresponding to

The molecular orbital shown below is described as

The molecular mass of Mohr's salt, FeSO_(4)(NH_(4))_(2)SO_(4). 6H_(2)O, is 392. Its equivalent mass is :

The molecular mass of K_(2)Cr_(2)O_(7) is 294 amu. It acts as oxidising agent in a redox titration. Its equivalent mass in acid medium will be :

The molecular mass of H_(3)PO_(3) is 82. Its equivalent mass, if it is completely neutralised, is:

The molecular mass of KMnO_(4) is M.Its equivalent mass in acidic medium will be :

The molecular mass of hydrogen peroxide is 34. What is the unit of molecular mass ?

The molecular mass of benzene is 78 amu. Its percentage composition is 92.31 % C and 7.69 % H. Determine the molecular formula of benzene.

The molecular mass of an organic acid was determind by the study of its barium salt. 4.290 g of salt was converted to free acid by the reaction with 21.64 mL of water of hydration per Ba^(2+) ion and the acid is monobasic. What is molecular weight of anhydrous acidgt

The molecular interaction responsible for hydrogen bonding in HF.

The molecular formular of a commerical resin used for exchanging ions in water softening is C_(8)H_(7)SO_(3)Na(Mol . Wt. of 206). What would be the maximum uptake of Ca^(2+) ions by the resin when expressed in mole per gram resin ?

The molecular formula of the compound formed from B and C will be :

The molecular formula of Napthacene is ……..

The molecular formula of Iron (III) Sulphate is ____ .

The molecular formula of inorganic benzene is "………….." and is obtained by heating the adduct of "………….." with "…………..".

The molecular formula of an organic compound is C_(4)H_(9)N. The volume of N_(2) that will be given by 0.2 g of the above compound at STP is …….. (ml)

The molecular formula of an organic compound is C_(4)H_(9)N. The volume of N_(2) that will be given by 0.2g of the above compound at STP is…(ml)

The molecular formula of a commercial resin used for exchanging ions in wter softening is C_(8)H_(7)SO_(3Na (mol.wt.206), What would be the maximum uptake of Ca^(2+) ions by resin when expressed in moe per gram resin?

The molecular fo rmula of the compound formed from 8 and C will be

The molecule electronic configuration of B_(2) is

The mole ratio of products H_(2), NaOH, CI_(2) formed in a Nelson cell method is

What is the mole percentage of O_(2) in a mixture of 7g of N_(2) and 8g of O_(2)?

The mole fraction of water in a solution of HCI is 0.78. Calculate the molality of the solution.

The mole fraction of solute in an aqueous solution is (1)/(112). The molality (m) of the solution is 0.1x. What is x?

The mole fraction of benzene in a solution in toluene is 0.40. Calculate the weight per cent of benzene in the solution.

The mole concept helps in handling a large number of atoms and molecules in stoichiometric calculations. Calculate the amount of CO_2 formed by the complete combustion of 80 g of methane as per the reaction CH_(4(g))+2O_(2(g))rarrCO_(2(g))2H_2O_((g)) (Atomic masses: C = 12.01u, H = 1.008u, O=16u)..

What is the number of hydrogen atoms in one mole of methane (CH_4)?

Define 1 mole

The molarity of the solution containing 2.8%(mass/volume) solution of KOH is : (Given atomic mass of K = 39)