94420 + Interview Questions in Chemistry in Class 12

1.	Can the same method of extraction be used for all metals.
Answer» Solution :The choice of method will DEPEND on the NATURE of the ore, TYPE of IMPURITY and ENVIRONMENTAL factors.

Discussion

2.	Can the acid chloride of an alpha-amino acid be made by treating it with SOCI_(2) ?
Answer» Solution :No. Two molecules of the INITIALLY formed `ALPHA`-amino acid chloride react with each otherf to form a dipeptide acid chloride which , in turn, reacts further to form tetrapeptide acid chloride , ETC. ,brgt `NH_(2)-CHR-COOH+SOCI_(2)to NH_(2)-CHR-COCI +SO_(2)+HCI` `underset("two molecules")underset(alpha-"Amino acid Chloride")(NH_(2) CHRCOCI+NH_(2)CHRCOCI) OVERSET(-HCI)to underset("Dipeptide acid chloride")(NH_(2)CHRCONHCHRCOCIto to to etc)`.

Discussion

3.	Can spontaneous reactions occur between Zn^(2+) and Au atoms ? (E_("ox")^(0) values for zinc and gold are +0.76V and-1.42 V resp.)
Answer» yes, `E_(CELL)^(0) = 2.18 V` no, `E_(cell)^(0)= -2.18 V` yes, `E_(cell^(0)) = 0.66 V` no, `E_(cell)^(0)= -0.66 V` SOLUTION :APPLICATION of EMF series.

Discussion

4.	can react with a maximum of ........... moles of CH_(3)I
Answer» 4 3 2 1 Answer :C

Discussion

5.	CaN pellets are coated with calcium silicate because:
Answer» CaN is explosive Can is hygroscopic CaN is water-soluble None Answer :B

Discussion

6.	Can PCl_5 act as an oxidising as well as a reducing agent ? Justify.
Answer» <P> Solution :Phosphorus has maximum oxidation state of +5 in `PCl_5`. It cannot INCREASE its oxidation state further and therefore, `PCI_5`, cannot ACT as a reducing agent. However, it can decrease its oxidation number from +5 to +3 or some lower value, therefore, `PCl_5` acts as an oxidising agent. For example, it oxidises Ag to AGCL, Sn to `SnCl_4` and `H_2` to HCl. `overset(0)(2Ag) + overset(+5)(PCl_5) to overset(+1)(2AgCl) + overset(+3)(PCl_3)` `overset(0)(Sn) + overset(+5)(2PCl_5) to overset(+4) (SnCl_4) + overset(+3)(2PCl_3)` `overset(+5)(PCl_5) + overset(0)(H_2) to overset(+3)(PCl_3) + overset(+1)(2HCl)` In these reactions, oxidation number of P decreases from +5 in `PCl_5` to +3 in `PCl_3` and that of Ag and H increases from 0 to +1 and that of Sn from 0 to +4. Thus, `PCl_5` acts as an oxidising agent.

Discussion

7.	Can PCl_(4) acts as an oxidising as well as a reducing agent? Justify.
Answer» Solution :Oxidation state of P in `PCl_(5)` is `+5`. Since P has five valence electrons in its valence shell, THEREFORE, it cannot increase its oxidation state BEYOND `+5` by donating its electrons therefore `PCl_(5)` cannot act as a REDUCING agent. HOWEVER, it can decrease its oxidation number from `+5` to `+3` or some lower value, therefore `PCl_(5)` acts as an oxidising agent. For example, it oxidises Ag to AgCl.

Discussion

8.	Can nucleic acids, proteins and starche be considered as step growth polymers ?
Answer» Solution :Yes. Step growth POLYMERS are actually CONDENSATION polymers in which largenumber of polynucleotides, `alpha`-amino acids and `alpha`-D-glucose units combine together with the loss of `H_(2)O` molecules leading to the formation of high molecular mass nucleic acids , PROTEINS and STARCH respectively.

Discussion

9.	Can nucleic acid, protein and starch be considered as step growth polymers ?
Answer» Solution :Yes, we can CONSIDER nucleic ACID, protein and starch as step growth polymer because during their polymerization REACTION, they lead to removal of water molecule or any NEUTRAL molecule also. Thus, we can also consider them as CONDENSATION polymers.

Discussion

10.	Can nucleic acids, proteins and starch be considered as step growth polymers ?
Answer» Solution :Nucleic acids, proteins and STARCH can be considered as STEP growth polymers because they are FORMED by the loss of a SIMPLE molecule LEADING to the formation of high molecular mass polymers.

Discussion

11.	Can NH_(4)Cl be replaced by any other ammonium salt for the precipitation of group III cations?
Answer» Solution :Yes `NH_(4)NO_(2)` can be used in place of `NH_(4)Cl` for the precipitation of group III cations ammonium sulphate cannot be used as it may PRECIPITATE `CA^(2+),BA^(2+)` and `Sr^(2+)` as insoluble SULPHATES.

Discussion

12.	CAN is hygroscope so its pellets are coated with calcuin silicate so as to product with calcium silicate so as to product from mixture.
Answer» ANSWER :T

Discussion

13.	Can Fe^(3+) oxidises Bromide to bromine under standard conditions? Given : E_(Fe^(3+\|Fe^(3+)))^(@)=0.771 ""E_(Br_(2)\|Br^(-))^(@)=1.09V
Answer» Solution :Required half cell REACTION `2Br^(-) RARR Br_(2)+2E^(-) ""(E_("ox")^(@))=-1.09V` `2Fe^(3+)+2e^(-) rarr 2Fe^(2+) "" (E_("red")^(@))=+0.771V` `2Fe^(3+)+2Br^(-) rarr 2Fe^(2+)+Br_(2)""(E_("cell")^(@)=?)` `E_("cell")^(@)=(E_("ox")^(@))+(E_("red")^(@))` `""=-1.09+0.771` `""=-0.319` V. `E_("Cell")^(@)` is - ve, `DELTA`G is +ve and the cell reaction is non-spontaneous. Hence `Fe^(3+)` cannot OXIDISES `Br^(-) " to " Br_(2)`.

Discussion

14.	Can Gatterman-Koch reaction be considered similar to Friedel-Craft acylation? Discuss.
Answer» Solution :Yes. Gattermann-Koch reaction can be considered similar to friedel-crafts ACYLATION. The reason being that in F.C. acylation reactions, benzene (or any other arene) is treated with an acid chlorie in presence of ANHYD. `AlCl_(3)`. SINCE HCOCl (FORMYL chloride) is not stable, therefore, in gattermann-koch reaction, it is prepared in situ by reacting CO with HCl gas in presence of anhydrous `AlCl_(3)`. thus, gattermann-Koch reaction is similar to F.C. acylation reaction.

Discussion

15.	Can filter paper dipped in silver nitrate solution instead of lead acetate paper be used for testing a sulphide?
Answer» SOLUTION :Yes, a paper dipped in `AgNO_(3)` when exposed to the VAPOURS of `H_(2)S` TURNS black DUE to the formation of silver sulphide. `2AgNO_(3)+H_(2)StoAg_(2)S+2HNO_(3)`

Discussion

16.	Can Fe^(3+)oxidises Bromide to bromime under standard conditions ? Given : E_(Fe^(3+)rfloorFe^(2+))^@=0.771""E_(Br_2\|Br^(-))^@=-1.09V
Answer» Solution :Required half cell reaction `2Br^(-)rarrBr^2+2e^(-)""(E_("ox")^@)=-1.09V` `2Fe^(3+)+2e^(-)rarr2Fe^(2+)""(E_("red")^@)=+0.771V` `2Fe^(3+)+2Br^(-)rarr2Fe^(2+)+Br_2""(E_("cell")^@)=? ` `E_("cell")^@=(E_("ox")^@)+(E_(red")^@)=-1.09+0.771=-0.319V` We KNOW that `DeltaG^@=-nFE_("cell")^@` If `E_("cell")^@" is "-ve, DeltaG` is +ve and the cell reaction is non - SPONTANEOUS: Hene , `FE^(3+)` cannot oxidise BROMIDE to BROMINE.

Discussion

17.	Can Fe^(3+) oxidise Bromide to bromine under standard conditions ? Given : E_(Fe^(3+)\|Fe^(2+))=0.771""E_(Br_(2)\|Br^(-))^(@)=-1.09V
Answer» Solution :Required half cell REACTION <BR> `2Br^(-)rarr Br^(2)+2e^(-)""(E_("ox")^(@))=-1.09V` `2Fe^(3+)+2e^(-)rarr2Fe^(2+)""(E_("red")^(@))=+0.771V` `2Fe^(3+)+2Br^(-)rarr 2Fe^(2+)+Br_(2)""(E_("cell")^(@))=?` `E_("cell")^(@)=(E_("ox")^(@))+(E_("red")^(@))=-1.09+0.771=-0.319V` We know that `DeltaG^(@)=-nFE_("cell")^(@)` If `E_("cell")^(@)` is `-ve`, `DeltaG` is `+ve` and the cell reaction is non - spontaneous. Hence, `Fe^(3+)` cannot oxidise Bromide to BROMINE.

Discussion

18.	Can FCl_(3) exist ? Comment.
Answer» Solution :No, because (i) F cannot exhibit valency more than one due to the ABSENCE of d-orbitals, (ii) three BIG sized CL atoms cannot be accommodated AROUND a SMALL F atom.

Discussion

19.	Can FCI_(3) exist ? Comment.
Answer» Solution :No, because F cannot exhibit VALENCY more than ONE. Further, three Cl atoms cannot be accommodated AROUND a SMALL F atom.

Discussion

20.	Can F^- be oxidised to F_2 by any substance listed in the electrochemical series?
Answer» SOLUTION :No, but it can be oxidised electrolytically

Discussion

21.	can exhibit
Answer» OPTICAL. Isomerism geometrical isomerism both none Answer :D

Discussion

22.	Can enzyebe called a polymer ?
Answer» SOLUTION :Yes, enzymes are BIOCATALYSTS which are PROTEINS and are thus POLYMERS.

Discussion

23.	Can enzyme be called a polymer ?
Answer» SOLUTION :ENZYMES are BIOCATALYST which being PROTEINS are REGARDED as polymers.

Discussion

24.	Can E_(cell)^(Theta) or Delta_(r)G^(Theta) for cell reaction ever be equal to zero ?
Answer» SOLUTION :* No, `E_(CELL)^(THETA)` or `Delta_(r)G^(Theta)` for cell reaction cannot be equal to ZERO, because if the VALUE is zero then reaction will be in equilibrium and so there will be no reaction in cell and such cell has no mean.

Discussion

25.	Can E_(cell)^(@) and Delta_(r)G^(@) for cell reaction ever be equal to zero?
Answer» Solution :No (`E_(CELL)` an be zero but not `E_(cell)^(@)`). Further, `DeltaG^(@)=-nFE_(cell)^(@)`. As `E_(cell)^(@)ne0`, therefore, `Delta_(R)G^(@)` also cannot be zero.

Discussion

26.	Can E_("cell")or Delta_(r)G^(@)for a cell reaction ever be equal to zero ?
Answer» ANSWER :No

Discussion

27.	Can colloidal solutions be filtered through normal filter papers ?
Answer» SOLUTION :No, because the pore SIZE of the NORMAL filter papers is larger than that of the colloidal PARTICLES.

Discussion

28.	Can chlorine gas be stored in a copper cylinder ? Given E^(Theta) (Cu^(2+) //Cu) = 0.34 Vand E^(Theta)( Cl_(2) // Cl^(-)) = 1.36 V .
Answer» SOLUTION :No , because REDUCTION POTENTIAL of `Cu^(2+)`\|Cu is LESS than that of `Cl_2`.

Discussion

29.	Can chlorine gas be stored in a copper cylinder? Given E_(Cu^(2+),Cu)^(@)=0.34V and E_(Cl^(2),Cl^(-))^(@)=1.36V
Answer» Solution :`Cu+Cl_(2)toCuCl_(2),i.e., Cu^(2+)+2CL^(-)` `E_(cell)^(@)=E_(Cu//Cu^(2+))^(@)+E_(Cl_(2)//2Cl^(-))^(@)=-0.34+1.36V=1.02V`. i.e., reaction takes PLACE. Hence, it cannot be stored.

Discussion

30.	Can chlorine exceptionally show hydrogen bonding in a compound ?
Answer» SOLUTION :In chloral hydrate, chlorine SHOWS INTERMOLECULAR hydrogen BONDING.

Discussion

31.	Can (CH_3)_3 CCHO undergo Cannizzaro reaction ?
Answer» Solution :`(CH_3)_3` CCHO can undergo Cannizzaro REACTION since it does not contain `alpha `- HYDROGEN . `2(CH_3)_3"CCHO"overset(NAOH)rarr(CH_3)_3"CCH"_(2)OH+(CH_3)_3"CCOONa"`

Discussion

32.	can be converted into azobenzene by reaction with
Answer» `LiAlH_(4)//"ether"` `Zn//NH_(4)CL` `Zn//NaOH, CH_(3)OH` `H_(2)//"Rancy "Ni`. Solution :`LiAiH_(4)//`Ether as well as `Zn//NH_(4)Cl` can cause reduction of nitrobenzene to AZOBENZENE

Discussion

33.	can be classified as:
Answer» Dehydration REACTION Williamson ALCOHOL synthesis reaction Williamson ETHER synthesis reaction Alcohol formation reaction Answer :C

Discussion

34.	Can any other reagent in place of limwe water be employed for identification of CO_(2) gas?
Answer» SOLUTION :YES, `M(OH)` can be EMPLOYED.

Discussion

35.	Can aquatic animals live in distilled water?
Answer» SOLUTION :No, because DISTILLED WATER does not have DISSOLVED OXYGEN]

Discussion

36.	Can aniline be prepared by Gabriel phthalimide reaction? Justify your answer.
Answer» Solution :No, ANILINE cannot be prepared by Gabriel phthalimide reaction. This method involves the TREATMENT of POTASSIUM phthalimide with aryl halides. But halides does not undergo nucleophilic SUBSTITUTION under ordinary conditions.

Discussion

37.	Can all the trioses are optically active ?
Answer» Solution :No. The ALDOTRIOSE, GLYCERALDEHYDE is OPTICALLY active DUE to presence of an asymmetric carbon. But ketotriose is optically inactive due to ABSENCE of asymmetric carbon.

Discussion

38.	Can absolute electrode potential of an electrode be measured ?
Answer» ANSWER :No

Discussion

39.	Can absolute value of electrode potential of an electrode be measured?
Answer» Solution :No because oxidation or REDUCTION cannot TAKE place laone. MOREOVER, it has to be determine with respect to a reference electrode.

Discussion

40.	Can a solution of 1 M copper sulphate be stored in a vessel made of nickel metal? Given that E_(Ni,Ni^(2+))^(@)=+0.25" volt ",E_(Cu,Cu^(2+))^(@)=-0.34 volt. Can nickel spatula be used to stir a solution of copper sulphate? Support your answer with a reason. E_(Ni^(2+)//Ni)^(@)=-0.25V,E_(Cu^(2+)//Cu)^(@)=+0.34V.
Answer» Solution :In this problem, we want to see whether the FOLLOWING reaction takes place or not: `Ni+CuSO_(4)toNiSO_(4)+CU,"i.E.,"Ni+Cu^(2+) to Ni^(2+) +Cu` By convention, the cell may be represented as: `Ni\|Ni^(2+)\|\|Cu^(2+)\|Cu` `E_(Ni,Ni^(2+))^(@)=+0.25" VOLT" and E_(Cu,Cu^(2+))^(@)=-0.34" volt"` Hence, the reduction potential will be `E_(Ni^(2+),Ni)^(@)=-E_(Ni,Ni^(2+))^(@)=-0.25" volt " and E_(Cu^(2+),Cu)^(@)=-E_(Cu,Cu^(2+))^(@)=+0.34" volt"` `E_(cell)^(@)=E_(RHS" electrode")^(@)-E_("L.H.S. electrode")^(@)=+0.34-(-0.25)=+0.59` volt Thus, EMF comes out to be POSITIVE. this implies that `CuSO_(4)` reacts with nickel. hence, `CuSO_(4)` cannot be sotred in nickel vessel.

Discussion

41.	Can a reaction have negative activation energy ?
Answer» Solution :According to Arrhenius eqn., `k="A e"^(-E_(a)//RT)`. If `E_(a)` were negative, the exponential factor can be written as `e^(X)` where `x=E_(a)//RT`. If `xltlt1`, we have `e^(x)=1+x+(x^(2))/(2!)+(x^(3))/(3!)+…=1+x""("NEGLECTING higher POWERS of x")` `=1+E_(a)//RT` `:.""k=A(1+E_(a)//RT)`, i.e., `kgtgtA` which is IMPOSSIBLE. Hence, `E_(a)` cannot be negative.

Discussion

42.	Can a reaction have negative activation energy. Justify.
Answer» Solution :`K=Ae^(-E_(a)//RT)` If `E_(a)" is "-ve, E^(-E_(a)//RT)=e^(x)" where "x=(E_(a))/(RT)` `e^(x) =1+x+(x^(2))/(2!) +(x^(3))/(3!)…..x LT lt lt 1+x=1+(E_(a))/(RT)` `k=A (1+(E_(a))/(RT))` `k gt gt A` Which is impossible HENCE `E_(a)` is never negative.

Discussion

43.	Can a nickel spoon be used to stir a solution of silver nitrate? Support your answer with reason. (E_(Ni^(2+),Ni)^(@)=-0.25V,E_(Ag^(+),Ag)^(@)=+0.80V).
Answer» Solution :The POSSIBLE REACTION is `Ni+2AG^(+)toNi^(2+)+2Ag` `E_(cell)^(@)=E_("cathode")-E_("anode")=0.80-(-0.25)=1.05V` As E.m.f. is positive, reaction is spontaneous.

Discussion

44.	Can a nickel spoon be used to stir a solution of silver nitrate. Support your answer with a reason given that : (E_(Ni^(2+)//Ni)^(@)=0.25V,E_(Ag^(+)//Ag)^(@)=+0.80V)
Answer» Solution :No, a nickel spoon cannot be used to STIR a silver nitrate solution. This is because Ni has lower SRP VALUE than AG. `:.` it will DISPLACE Ag from `AgNO_(3)` solution, `:.` the solution will DESTROYED. `Ni+2AgNO_(3)toNi(NO_(3))_(2)+2Ag`.

Discussion

45.	Can a gas mixed with another gas forms a colloidal solution? Give reason for your answer.
Answer» SOLUTION :No, because gas-gas MIXTURE is ALWAYS HOMOGENEOUS.

Discussion

46.	Can a copolymer be formed in both addition and condensation polymerisation ? Explain with examples.
Answer» SOLUTION :Yes.Buna-S, Buna-N : ADDITION polymer Nylon-6, 6, TERYLENE : CONDENSATION

Discussion

47.	Camphor is used as solvent to determine molecular weight of non-volatile solute by Rast method because. For camphor:
Answer» Being cheap High m.pt. Molal DEPRESSION CONSTANT is high None Answer :C

Discussion

48.	Camphor is often used in molecular mass determination because
Answer» it is readily available it has a very HIGH cryoscopic constant it is volatile it is solvent for organic substances Solution :Camphor has a very high cryoscopic constant `(=39.7^(@))`. HENCE, it gives a largedepression in MELTING point when an organic SOLUTE is dissolved in it.

Discussion

49.	Classify the following substances into elements, compounds and mixtures : (i) Milk (ii) 22-carat gold (iii) Iodized table salt (iv) Diamond (v) Smoke (vi) Steel (vii) Dry ice (ix) Mercury (x) Air (xi) Aerated drinks (xii) Glucose (xiiii) Petrol/Diesel/Kerosene oil (xiv) Steam (xv) Cloud.
Answer» Solution :ELEMENTS - (iv),(IX), Compounds - (VIII), (xii), (xiv), (xv) Mixture - (i), (ii), (iii), (V), (VI), (vii), (x), (xi), (xiii).

Discussion

50.	Calorific value of carbohydrates is approximately:
Answer» 4.0 kcal/g 16.0 kcal/g 20 kcal/g 9.0 kcal/g Answer :B

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Can the same method of extraction be used for all metals.

Can the acid chloride of an alpha-amino acid be made by treating it with SOCI_(2) ?

Can spontaneous reactions occur between Zn^(2+) and Au atoms ? (E_("ox")^(0) values for zinc and gold are +0.76V and-1.42 V resp.)

can react with a maximum of ........... moles of CH_(3)I

CaN pellets are coated with calcium silicate because:

Can PCl_5 act as an oxidising as well as a reducing agent ? Justify.

Can PCl_(4) acts as an oxidising as well as a reducing agent? Justify.

Can nucleic acids, proteins and starche be considered as step growth polymers ?

Can nucleic acid, protein and starch be considered as step growth polymers ?

Can nucleic acids, proteins and starch be considered as step growth polymers ?

Can NH_(4)Cl be replaced by any other ammonium salt for the precipitation of group III cations?

CAN is hygroscope so its pellets are coated with calcuin silicate so as to product with calcium silicate so as to product from mixture.

Can Fe^(3+) oxidises Bromide to bromine under standard conditions? Given : E_(Fe^(3+|Fe^(3+)))^(@)=0.771 ""E_(Br_(2)|Br^(-))^(@)=1.09V

Can Gatterman-Koch reaction be considered similar to Friedel-Craft acylation? Discuss.

Can filter paper dipped in silver nitrate solution instead of lead acetate paper be used for testing a sulphide?

Can Fe^(3+)oxidises Bromide to bromime under standard conditions ? Given : E_(Fe^(3+)rfloorFe^(2+))^@=0.771""E_(Br_2|Br^(-))^@=-1.09V

Can Fe^(3+) oxidise Bromide to bromine under standard conditions ? Given : E_(Fe^(3+)|Fe^(2+))=0.771""E_(Br_(2)|Br^(-))^(@)=-1.09V

Can FCl_(3) exist ? Comment.

Can FCI_(3) exist ? Comment.

Can F^- be oxidised to F_2 by any substance listed in the electrochemical series?

can exhibit

Can enzyebe called a polymer ?

Can enzyme be called a polymer ?

Can E_(cell)^(Theta) or Delta_(r)G^(Theta) for cell reaction ever be equal to zero ?

Can E_(cell)^(@) and Delta_(r)G^(@) for cell reaction ever be equal to zero?

Can E_("cell")or Delta_(r)G^(@)for a cell reaction ever be equal to zero ?

Can colloidal solutions be filtered through normal filter papers ?

Can chlorine gas be stored in a copper cylinder ? Given E^(Theta) (Cu^(2+) //Cu) = 0.34 Vand E^(Theta)( Cl_(2) // Cl^(-)) = 1.36 V .

Can chlorine gas be stored in a copper cylinder? Given E_(Cu^(2+),Cu)^(@)=0.34V and E_(Cl^(2),Cl^(-))^(@)=1.36V

Can chlorine exceptionally show hydrogen bonding in a compound ?

Can (CH_3)_3 CCHO undergo Cannizzaro reaction ?

can be converted into azobenzene by reaction with

can be classified as:

Can any other reagent in place of limwe water be employed for identification of CO_(2) gas?

Can aquatic animals live in distilled water?

Can aniline be prepared by Gabriel phthalimide reaction? Justify your answer.

Can all the trioses are optically active ?

Can absolute electrode potential of an electrode be measured ?

Can absolute value of electrode potential of an electrode be measured?

Can a reaction have negative activation energy ?

Can a reaction have negative activation energy. Justify.

Can a nickel spoon be used to stir a solution of silver nitrate? Support your answer with reason. (E_(Ni^(2+),Ni)^(@)=-0.25V,E_(Ag^(+),Ag)^(@)=+0.80V).

Can a nickel spoon be used to stir a solution of silver nitrate. Support your answer with a reason given that : (E_(Ni^(2+)//Ni)^(@)=0.25V,E_(Ag^(+)//Ag)^(@)=+0.80V)

Can a gas mixed with another gas forms a colloidal solution? Give reason for your answer.

Can a copolymer be formed in both addition and condensation polymerisation ? Explain with examples.

Camphor is used as solvent to determine molecular weight of non-volatile solute by Rast method because. For camphor:

Camphor is often used in molecular mass determination because

Classify the following substances into elements, compounds and mixtures : (i) Milk (ii) 22-carat gold (iii) Iodized table salt (iv) Diamond (v) Smoke (vi) Steel (vii) Dry ice (ix) Mercury (x) Air (xi) Aerated drinks (xii) Glucose (xiiii) Petrol/Diesel/Kerosene oil (xiv) Steam (xv) Cloud.

Calorific value of carbohydrates is approximately: