52671 + Interview Questions in Chemistry in Class 11

1.	Can we separate a mixture of benzoic acid and camphor by sublimation ?
Answer» ANSWER :No

Discussion

2.	Can we remove completely temporary hardness due to Mg(HCO_(3))_(2) by boiling ?
Answer» SOLUTION :Temporary HARDNESS of water due to `Mg(HCO_(3))_(2)` can be completely removed by boiling because SOLUBLE `Mg(HCO_(3))_(2)` is converted into insoluble `MfCO_(3)` which can be easily removed by filtration. `underset("soluble")(Mg(HCO_(3))_(2))overset("boil")tounderset("insoluble")(MgCO_(3))+CO_(2)uarr+H_(2)O`

Discussion

3.	Can we purify impure sugar by sublimation process ?
Answer» ANSWER :No

Discussion

4.	Can we have a diatomic molecule with its ground state moleculer orbitals full with electrons ? Give a reason for your answer .
Answer» Solution :No. Becausebond order becomes ZERO, e.g., in CASE of `He_(2), Be_(2), Ne_(2)` , etc . Note that in `H_(2), sigma _(1s)` M.O. is full but`sigma_(1s)^(**)` is EMPTY .

Discussion

5.	Can we estimate oxygen in an organic compound ?
Answer» Solution :Yes. But usually it is INDIRECTLY estimated by subtracting the sum of percentages of all the ELEMENTS PRESENT in an organic COMPOUND from 100.

Discussion

6.	Can we estimate oxygen in a compound ?
Answer» SOLUTION :YES, by both THEORETICAL and PRACTICAL METHOD.

Discussion

7.	Can we convert graphite into diamond ? Which one is more stable and why ?
Answer» Solution :Theoretically,graphite is CONVERTED into diamond by absorption of heat but besides heat, the conversion requiressome other drastic conditions. Hence, the conversion is noteasy. As graphiteabsorbs energy to change intodiamon, diamond has HIGHER energy and hence LESS STABLE.

Discussion

8.	Can we detect oxygen in a compound by Lassaigne's test ?
Answer» ANSWER :No

Discussion

9.	Can we apply Heisenberg's uncertainty principle to a stationary electron? Why ?
Answer» SOLUTION :No, for a stationary electron, VELOCITY = 0 and THUS, POSITION can be measured accurately.

Discussion

10.	Can we apply Heisenberg's uncertaintly principle to a stationary electron ? Why or why not ?
Answer» Solution :No, because, VELOCITY = 0 and position can be MEASURED ACCURATELY ?

Discussion

11.	Can the reaction Cr_(2)O_(7)^(2-)+H_(2)O rarr 2CrO_(4)^(2-)+2H^(+) be regarded as a redox reaction?
Answer» Solution :Oxidation number of Cr in `Cr_(2)O_(7)^(2-)=+6` oxidation number of Cr in `CrO_(4)^(2-)=+6` SINCE during this reaction the oxidation number of Cr has neither decreased nor INCREASED therefore the above reaction cannot be regarded as a redox reaction

Discussion

12.	Can the oxidation number of an atom in a chemical species be fractional? Illustrate by an example?
Answer» SOLUTION :YES, it can be fractional. For example, OXIDATION number of Pb in `Pb_3O_4=+8/3`

Discussion

13.	Can the absolute value of internal energy by determined ? Why or why not?
Answer» SOLUTION :No, because it is the SUM of DIFFERENT TYPES ofenergies some of which cannot be DETERMINED.

Discussion

14.	Can sodium bicarbonate make water hard ?
Answer» SOLUTION :Sodium bicarbonate cannot MAKE WATER hard because soaps themselves are sodium salts of fatty ACIDS which are soluble in water.

Discussion

15.	Can P_x overlap a p_y orbital ? Why or why not?
Answer» SOLUTION :No, They cannot OVERLAP because their ORIENTATIONS and SYMMETRIES are notsame.

Discussion

16.	Can propene and propyne be distinguished by using Baeyer's reagent? If not, what is the suitable reagent?
Answer» Solution :Propene and propyne cannot be distinguished by using Baeyer.s reagent, because both can decolourise the pink colour of Baeyer.s reagent. The suitable REAGNET is Tollen.s reagnet. Propyne would GIVE white PRECIPITATE due to the PRESENCE of acidic hydrogen, whereas propene does not contain acidic hydrogen, and so cannot give precipitate.

Discussion

17.	Can phosphorus with outer electronic configuration 3s^2, 3p^3 form PH_5 ?
Answer» Solution :ALTHOUGH phosphorus exhibits +3 and +5 oxidation STATES, it cannot form `PH_5`. Besides some other considerations, high `Delta_a H` value of dihydrogen and `Delta_(eq)H` value of hydrogen do not FAVOUR to exhibit the highest oxidation state of P, and CONSEQUENTLY the formation of `PH_5`.

Discussion

18.	Can phosphorus with other electronic configuration 3s^(2) 3p^(3) from PH_(5)?
Answer» Solution :Although P shows oxidation STATES of +3 and +5 , it cannot FORM `PH_(5)` . Due to high `Delta_(H-H)`(435.88 KJ `mol^(-1)`) and slightly negative `Delta`eg H(-73 KJ `mol^(-1)`) dihydrogen acts only as a weak oxidising AGENT. Therefore, it can oxidise P to +3 oxidation state but not to its HIGHEST oxidation state of +5 . Thus, P forms `PH_(3)` but not `PH_(5)`

Discussion

19.	Can PCl_(5) act as an oxidising as well as reducing agent ? Justify.
Answer» Solution :The oxidation state of P in `PCl_(5)" is "+5`. SINCE P has five electrons in its valence shell, therefore, it cannot increase its oxidation state beyond +5 by donating electrons, therefore, `PCl_(5)` cannot act as a reducing agent. HOWEVER, it can decrease its oxidation number from +5 ot +3 or some lower value, therefore, `PCl_(5)` acts as an oxidisting agent. For example, it oxidises Ag to AgCl, Sn to `SnCl_(4)andH_(2)` to HCl. `2overset(0)Ag+overset(+5)PCl_(5)to2overset(+1)AgCl+overset(+3)PCl_(3),overset(0)Sn+2overset(+5)PCl_(5)tooverset(+4)SnCl_(4)+2overset(+3)PCl_(3)` `Poverset(+5)Cl_(5)+H_(2)tooverset(+3)PCl_(3)+2overset(+1)HCl` In These reacitons, oxidation number of P decreases form +5 in `PCl_(5)` to +3 in `PCl_(3)` and that of Ag and H INCREASES from 0 to +1 and that of Snfrom 0 to +4. Thus, `PCl_(5)` acts as an oxidising agent.

Discussion

20.	Can oxygen exhibit positive oxidation numbers in its compounds?
Answer» Solution :Yes. In FLUORIDES, oxygen exhibits positive OXIDATION STATES. Oxidation state in `O_(2)F_(2)` is +1.

Discussion

21.	Can oxidation number be zero ? Illustrte .
Answer» ANSWER :YES

Discussion

22.	Can -NO_(2) group act as secondary suffix ?
Answer» SOLUTION :No, it is a PRIMARY SUFFIX or SUBSTITUENT.

Discussion

23.	Can methane be obtained by the kolbe's electrolysis ? Why ?
Answer» Solution :Methane cannot be prepared by the Kalbe.s electrolysis because has only 1 CARBON. In electrolysis, there is a attachment of 2 alkyl group means there are 2 or more carbon ATOMS therefore attest 2 carbon MINIMUM alkane is FORMED. `2RCOO^(-)Na^(+) overset("Electrolysis")RARR R-R+2CO_(2)+2NaOH`

Discussion

24.	Can marine species live in distilled water ? Justify .
Answer» SOLUTION :No, because DISTILLED WATER does not contain dissolved oxygen.

Discussion

25.	Can marine species live in distilled water ?
Answer» Solution :No, because DISTILLED `H_(2)O` does not contain DISSOLVED `O_(2)`

Discussion

26.	Can Li or K metal be used in place of Na during detection of elements by Lassaigne's test ?
Answer» Solution :Li is not used because it is much LESS REACTIVE than NA and hence requires times to complete fusion. K is not because it readily catches fire and hence quite difficult to HANDLE.

Discussion

27.	Can interstitial hydrides be used for storing hydrogen gas ? Comment .
Answer» Solution :When d-or f-block elements or their alloys are heated with `H_(2)` , they absorb `H_(2)` to from interstitial HYDRIDES when needed the `H_(2)` GAS can be released on mild HEATING. Thus , interstitial hydrides can be USED for STORING `H_(2)` gas.

Discussion

28.	Can glycerol be purified by simple distillation ?
Answer» ANSWER :No

Discussion

29.	Can distilled water be the called as deionised water ?
Answer» Solution :YES. Distilled water does not contain any CATIONS and ANIONS and hence can be called as deinoized water.

Discussion

30.	Can distilled water be called as deionised water?
Answer» SOLUTION :Distilled WATER is ALSO be called as deio nised water, because it does not CONTAIN any cations and anions.

Discussion

31.	Can demineralised water be used for drinking ?
Answer» SOLUTION :It is not useful for DRINKING purpose, though it is pure. Minerals or SALTS must be added to drinking water, as they are REQUIRED to maintain proper HEALTH

Discussion

32.	Can chlorine gas be stored in a copper cylinder ? Given E^@(Cu^(2+)\|Cu)=-0.34V and E^@(Cl^(-)\|Cl)=1.36V
Answer» ANSWER :No

Discussion

33.	can be distinguish by
Answer» `CHCl_(3) +KOH` `NaNO_(2)+HCl` FOLLOWED by `beta`-Napthol `CS_(2)+HgCl_(2)` Na metal Solution :

Discussion

34.	can be differentiated by :
Answer» `FeCl_(3)` NaOH `NaNO_(2) + HCl` FEHLING's solution Answer :A

Discussion

35.	can be differentiated by :
Answer» NaOH Na metal `NaHCO_(3)` `FeCl_(3)` Answer :C

Discussion

36.	can be differentiated by :
Answer» carbylamine reaction <BR>iodoform test cold `KMnO_(4)` `Br_(2)-H_(2)O` Answer :A

Discussion

37.	Can an organic compound have two OH groups attached to the same carbon atom ?
Answer» ANSWER :No

Discussion

38.	Can an element have variable equivalent masses ?
Answer» ANSWER :YES

Discussion

39.	Can anelementwith atomicnumber126, if discoveredbe accommodate in thepresentset up ofthe longform of theperiodictabel ?
Answer» SOLUTION :No. themaximumnumberof elementswhichcan beaccommodated in the presentset upof thelong formof the priodictable is`118. thereforefillingof 8s-orbital shallbeginwhichwillaccommodate only twoelectrons . After 8s-orbitals , the filingof 5g- orbitals will begin. Sincewe donot haveanyprovision forg- blockelementsin THEPRESENTSET up OT the longformof theperiodictabletherefore and elementswithatomicnumber126 , itdiscoveredcannotbe accommodatedin thepresentset upof the longformof theperiodictable .

Discussion

40.	Can AgNO_(3) test be used for the detection of fluoride ion in Lassaigne's extract ?
Answer» Solution :No. The reason being that AGF is highly soluble in WATER and HENCE `F^(-)` ion PRESENT in Lassaigne's extract does not PRODUCE any precipitate of AgF. `underset("Lassaigne's extract")(NaF)+AgNO_(3) rarr "No pp.t of AgF"`

Discussion

41.	Can a Van der Waals gas with a=0 be liquefied? Explain.
Answer» SOLUTION :(i) a=0 for a Vander waals gas i.e for a REAL gas. Vander waals constant a=0. It cannot be liquefied. (ii) If a=0, there is a vary less inter action between the molecules of the gas (iii) a is the measure of strength of vander waals FORCE of ATTACTION between the molecules of the gas. (IV) If a is equal to zero, the vander waals force of attraction is very less and the gas cannot be liquefied.

Discussion

42.	Can a substance exist in all the three states of matter? Give an example.
Answer» SOLUTION :YES, WATER

Discussion

43.	Can a solutionof 1 M ZnSO_(4) be stored ina vessel made of coppr ? Given that E_(Zn,Zn^(2+))^(@)=+0.76 "volt and" E_(Cu^(2+))^(@)Cu=0.34 volt
Answer» Solution :Since `E_(Fe^(2+),Fe)^(@)=-E_(Zn,Zn^(2+))^(@)=-0.765V` is at LOWER potential than `E_(Cu^(2+),Cu)^(@)=0.34V` therefore Zn can only LOSE electrons to `Cu^(2+)` ions conversely `Zn^(2+)` cannot accept electrons from Cu and hence the following reaction will not occur `Zn^(2+)+Curarr +Cu^(2+)` In other WORDS `ZnSO_(4)` solution can be SAFELY stored in a copper vessel

Discussion

44.	Can a solution o f1 M copper suplhate be stroed in a vessel made of nickel metal ? Give that E^(@) Ni,Ni^(2+)=+0.25"volt" , E^(@) Cu,Cu^(2+)=-34volt or is it possible to stroe copper suplhate solution in a nickel vessel ?
Answer» Solution :In this PROBLEM we want to see whether the following reaction takes place or not ltbnr?GT `Ni+CuSO_(4) RARR NiSO_(4)+Cu, i.e NiCu^(2+) rarr Ni^(2+)+Cu` By conventin the cell may be represented as `NiNi^(2+)\|\|Cu^(2+)\|Cu` We given oxidation potential as `E_(Ni,Ni^(2))^(@)=+0.25` volt and `E_(Cu,Cu^(2))^(@)=-0.34` volt Henc by reversing the SIGN of oixdation potential the reducitn potential s will Thus EMF comes out to be positive this imlies that `CuSO_(4)` reacts with nickel hence`CuSO_(4)` solution connot be stroed in a nickel vessel Alternatively since `E_(Ni^(2+),Ni)=-0.25` V islower than `E_(Cu^(2+),Cu)^(@)=+0.34` V therefore Ni can easily lose electrons to `Cu^(2+)` ions in other words the following rection `Ni+Cu^(2+)rarrNi^(2+)+Cu` Will occur thus `CuSO_(4)` solution cannot be stored in a nickel vessel

Discussion

45.	Can a gas with a = 0 be liquefied?
Answer» SOLUTION :If a liquid is HEATED to the CRITICAL temperature of its vapour, the vapour PRESSURE of liquid becomes EQUAL to the vapour pressure of its vapour

Discussion

46.	Can a less electropositive metal displace more electropositive metal from its salt solution ?
Answer» ANSWER :No

Discussion

47.	Can 2-pentene show geometrical isomerism ?
Answer» SOLUTION :YES GEOMETRICAL ISOMERS are

Discussion

48.	Camphor is purified of
Answer» DISTILLATION vacuum distillation SUBLIMATION STEAM distillation Answer :C

Discussion

49.	Oxidation number of Cr inK_3CrO_8 is
Answer» Solution :`K_(3)CrO_(8)` is `K_3[CR(O_2)_(4)]` i.e ., 4 (O-O) bond `:.` OXIDATION no. of.= Cr + 5 .

Discussion

50.	Calssify the following as acid or base according to Bronsted-Lowry theory and name their corresponding conjugate base or acid (i) NH_(3) " " (ii) CH_(3)CO O^(-) (iii) H_(3)O^(+) "" (iv) H^(-)" "(v) HO O^(-) " " (vi) S_(2)O_(8)^(2-).
Answer» SOLUTION :According to Bronsted-Lowry THEORY, an acid is a substance which can donate a proton while base is a substance which can accept a proton. (i) `NH_(3)` is a Bronsted base because it can accept a proton. Its conjugate acid is `NH_(4)^(+)`. `NH_(3)` is also a Bronsted acid because it can donate a proton. Its conjugate base in `NH_(2)^(-)`. (ii) `CH_(3)CO O^(-)` is a Bronsted base `(CH_(3)CO O^(-) + H^(+) rarr CH_(3)CO OH)`. Its CONJUGATEACID is `CH_(3)CO OH`. (iii) `H_(3)O^(+)` is a Bronsted acid `(H_(3)O^(+) rarr H_(2)O+H^(+))`. Its conjugate base is `H_(2)O`. (iv) `H^(-)` is a Bronsted base `(H^(_)+H^(+) rarr H_(2) "in the reaction" H^(-) + H_(2)O hArrH_(2)+OH^(-))`. Its conjugate acid is `H_(2)`. (V) `HO O^(-)` is a Bronsted acid (`HO O^(-) rarr O_(2)^(2-) + H^(+)` in the reaction `H O O^(-) + H_(2)O rarr O_(2)^(2-) + H_(3)O^(+)`). Its conjugate acid is `O_(2)^(2-)` (peroxide ion). (vi) `S_(2)O_(8)^(2-) ` is a Bronsted base `(S_(2)O_(8)^(2-) + 2 H^(+) rarr 2 HSO_(4)^(-) " in the reaction" S_(2)O_(8)^(2-) + 2 H_(2)O hArr 2 HSO_(4)^(-) + OH^(-))`. Its conjugate acid is `HSO_(4)^(-)`.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Can we separate a mixture of benzoic acid and camphor by sublimation ?

Can we remove completely temporary hardness due to Mg(HCO_(3))_(2) by boiling ?

Can we purify impure sugar by sublimation process ?

Can we have a diatomic molecule with its ground state moleculer orbitals full with electrons ? Give a reason for your answer .

Can we estimate oxygen in an organic compound ?

Can we estimate oxygen in a compound ?

Can we convert graphite into diamond ? Which one is more stable and why ?

Can we detect oxygen in a compound by Lassaigne's test ?

Can we apply Heisenberg's uncertainty principle to a stationary electron? Why ?

Can we apply Heisenberg's uncertaintly principle to a stationary electron ? Why or why not ?

Can the reaction Cr_(2)O_(7)^(2-)+H_(2)O rarr 2CrO_(4)^(2-)+2H^(+) be regarded as a redox reaction?

Can the oxidation number of an atom in a chemical species be fractional? Illustrate by an example?

Can the absolute value of internal energy by determined ? Why or why not?

Can sodium bicarbonate make water hard ?

Can P_x overlap a p_y orbital ? Why or why not?

Can propene and propyne be distinguished by using Baeyer's reagent? If not, what is the suitable reagent?

Can phosphorus with outer electronic configuration 3s^2, 3p^3 form PH_5 ?

Can phosphorus with other electronic configuration 3s^(2) 3p^(3) from PH_(5)?

Can PCl_(5) act as an oxidising as well as reducing agent ? Justify.

Can oxygen exhibit positive oxidation numbers in its compounds?

Can oxidation number be zero ? Illustrte .

Can -NO_(2) group act as secondary suffix ?

Can methane be obtained by the kolbe's electrolysis ? Why ?

Can marine species live in distilled water ? Justify .

Can marine species live in distilled water ?

Can Li or K metal be used in place of Na during detection of elements by Lassaigne's test ?

Can interstitial hydrides be used for storing hydrogen gas ? Comment .

Can glycerol be purified by simple distillation ?

Can distilled water be the called as deionised water ?

Can distilled water be called as deionised water?

Can demineralised water be used for drinking ?

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

can be distinguish by

can be differentiated by :

can be differentiated by :

can be differentiated by :

Can an organic compound have two OH groups attached to the same carbon atom ?

Can an element have variable equivalent masses ?

Can anelementwith atomicnumber126, if discoveredbe accommodate in thepresentset up ofthe longform of theperiodictabel ?

Can AgNO_(3) test be used for the detection of fluoride ion in Lassaigne's extract ?

Can a Van der Waals gas with a=0 be liquefied? Explain.

Can a substance exist in all the three states of matter? Give an example.

Can a solutionof 1 M ZnSO_(4) be stored ina vessel made of coppr ? Given that E_(Zn,Zn^(2+))^(@)=+0.76 "volt and" E_(Cu^(2+))^(@)Cu=0.34 volt

Can a solution o f1 M copper suplhate be stroed in a vessel made of nickel metal ? Give that E^(@) Ni,Ni^(2+)=+0.25"volt" , E^(@) Cu,Cu^(2+)=-34volt or is it possible to stroe copper suplhate solution in a nickel vessel ?

Can a gas with a = 0 be liquefied?

Can a less electropositive metal displace more electropositive metal from its salt solution ?

Can 2-pentene show geometrical isomerism ?

Camphor is purified of

Oxidation number of Cr inK_3CrO_8 is

Calssify the following as acid or base according to Bronsted-Lowry theory and name their corresponding conjugate base or acid (i) NH_(3) " " (ii) CH_(3)CO O^(-) (iii) H_(3)O^(+) "" (iv) H^(-)" "(v) HO O^(-) " " (vi) S_(2)O_(8)^(2-).