94420 + Interview Questions in Chemistry in Class 12

1.	Solid AB has the NaCZ structure. Atom A occupy the corners of the cubic unit cell. If all the face centered atoms along one of the axes are removed, then the resultant stoichiometry of the solid is
Answer» `AB_(2)` `A_(2)B` `A_(4)B_(3)` `A_(3)B_(4)` Answer :D

Discussion

2.	Solid (A) reacts with strong aqueous NaOH liberating a foul smelling gas (B) which spontaneously burn in air giving smoky rings. A and B are respectively
Answer» `P_(4)` (red) and `PH_(3)` `P_(4)` (white) and `PH_(3)` `S_(8)` and `H_(2)S` `P_(4)` (White) and `H_(2)S` ANSWER :A::B::C::D

Discussion

3.	Solid (A) reacts with strong aqueous NaOH liberating a foul smelling gas (B) which spontaneouly burn in air giving smoky rings. A and B are respectively …………… .
Answer» <P>`P_(4)" (red) and "PH_(3)` `P_(4)" (white) and "PH_(3)` `S_(8) andH_(2)S` `P_(4)" (white) and "H_(2)S` Solution :`P_(4)" (white) and "PH_(3)`

Discussion

4.	Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it ?
Answer» Solution :`SiO_(2)` (quartz) or SIC (CARBORUNDUM) show such properties. They are called network solids.

Discussion

5.	Solid A is very hard, insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?
Answer» SOLUTION :A is a COVALENT OT NETWORK SOLID.

Discussion

6.	Solid A + H_(2)O rarr (B) (while turbity which redissolves in HCI) Identify D
Answer» `Br_(2)` `HCI` `I_(2)` `CI_(2)` Solution :`underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("WHITE PPT.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCL` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(DELTA)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)`

Discussion

7.	Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?
Answer» SOLUTION :The SOLID A is a COVALENT solid.

Discussion

8.	Solid A is a very hard electrical insulator in solid as well as in molten state, and melts at extremely high temperature. What type of solid is it ?
Answer» Solution :Covalent or Network solid LIKE `SiO_(2)` (quartz) or `SIC` or C (DIAMOND).

Discussion

9.	Solid A + H_(2)O rarr (B) (while turbity which redissolves in HCI) Identify B
Answer» BiOCI `BaS` `BaCI_(3)` NONE of these Solution :`UNDERSET((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("BLACK ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)`

Discussion

10.	Solid A + H_(2)O rarr (B) (while turbity which dissolves in HCI) Identify C
Answer» BiOCI `Bi_(2)S_(3)` `BiCI_(3)` `H_(2)S` Solution :`underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("BLACK ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)`

Discussion

11.	Solid A + H_(2)O rarr (B) (while turbity whichredissolves in HCI) Identify A
Answer» `BiOCI` `BI_(2)S_(3)` `BiCI_(3)` `BaSO_(4)` Solution :`underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCL"))underset((B))underset("White PPT.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) DARR +2HNO_(3)`

Discussion

12.	Solid A + H_(2)O rarr (B) (while turbity which dissolves in HCI) Identify E
Answer» `Hg_(2)(NO_(3))_(2)` `HCI` `Hg_(2)CI_(2)` `HNO_(3)` Solution :`underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCL"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)OVERSET(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) DARR +2HNO_(3)`

Discussion

13.	Solder in an alloy of :
Answer» PB, SB and SN Pb and Sn Pb , Bi and Sn Sn , Sb andCu Answer :B

Discussion

14.	Solar ultraviolet radiation is absorbed by :
Answer» Exosphere Ionosphere Ozonosphere Stratosphere Answer :D

Discussion

15.	Soil containing both Al and Fe is called
Answer» Laterite Bauxite Pedalfers Clay Answer :C

Discussion

16.	Sol of egg albumin is prepared by
Answer» mixing the YOLK and white of the egg by BEATING and then adding it into water adding only the yolk of the egg into water adding only the white of the egg into COLD water adding the white of the egg into hot water Answer :C

Discussion

17.	Sol particles of ferric hydroxide (I) and arsenlous sulphate (II) are positively and negatively charged respectively . Which of the following are correct-
Answer» coagulation will take place when sol (II) compared to sol (II) `Na_(2)SO_(4)` solution will QUICKLY COAGULATE sol (I) compared to sol (II) particles of sol (I) will exhibit anaphoresis and that of sol (II) will exhibit cataphoresis sol (I) is reversible and sol (II) is irreversible Answer :A::B

Discussion

18.	Soilsalinity can be measured by
Answer» Potentiometer Calorimeter CONDUCTIVITY meter Allof these Answer :C

Discussion

19.	Softerning of lead means:
Answer» COVERSION of lead in to PbO Conversion of lead into `Pb_3O_4` Removal of METALLIC impuriies from lead Washing lead with `HNO_3` FOLLOWED by dilute alkali solution Answer :C

Discussion

20.	Soft heavy metal melts at 30^(@)C and is used in making heat sensitive thermometers the metal is
Answer» GALLIUM SODIUM POTASSIUM CAESIUM ANSWER :A

Discussion

21.	Soft soaps are
Answer» Sodium salts of FATTY acids Potassium salt of fatty acids CONTAINING excess of free alkali Potassium salt of fatty acids containing no of free alkali Calcium salts of fatty acids Answer :B

Discussion

22.	Soft d-block elements occurs as
Answer» silphide ORE OXIDE ore NITRIDE ore HYDROXIDE ore Answer :A

Discussion

23.	Soft drink and baby-feeding bottles are generally made of:
Answer» Polyurea polyester polymide Polystyrene Answer :D

Discussion

24.	Soft drinks and baby feeding bottles are generally made up of
Answer» Polyester Polyurethane POLYSTYRENE POLYAMIDE. Answer :C

Discussion

25.	Soft and pliable steel is obtained by :
Answer» TEMPERING NITRIDING Annealind NONE ANSWER :C

Discussion

26.	Sodium when heated in a current of dry ammonia gives
Answer» SODIUM nitrate Sodium hydride Sodium amide Sodium azide Solution :`2Na+2NH_(3) to 2NaNH_(2) +H_(2)`

Discussion

27.	Sodium zeolite is :
Answer» `NaAlSi_2O_6` `Na_2Al_2Si_2O_3` `Na_2Al_2Si_2O_8` `NaAl_2Si_2O_8` ANSWER :C

Discussion

28.	Sodium vapour is paramagnetic, but cations of sodium are diamagnetic, while vapour magnesium as well as cations of magnesium are diamagnetic. Explain.
Answer» Solution : ATOMS or ions with UNPAIRED ELECTRONS are paramagnetic. Diamagnetism is DUE to the absence of unpaired electrons. Na VAPOUR has unpaired electrons. Hence, paramagnetic. Number of electrons in `Na^(+)` is 10. They have no unpaired electrons. Hence,diamagnetic. Both Mg and `Mg^(2+)`have

Discussion

29.	Sodium thiosulphate, Na_(2)S_(2)O_(3)*5H_(2)O is used in photography to:
Answer» REDUCE the silver bromide to METALLIC silver Convert the metallic silver to silver salt Reduce undecomposed AgBr as soluble silver thiosulphate complex Remove REDUCED silver Answer :C

Discussion

30.	Sodium thiosulphate is used to remove the unexposed AgBr from photographic films by forming a complex. In this complex of silver, the coordination number ofsilver is:
Answer» `2` `4` `6` `8` ANSWER :B

Discussion

31.	Sodium thiosulphate, Na_2S_2O_3.5H_2O is used in photography to:
Answer» Reduce the silver bromide GRAINS to METALLIC silver Convert the metallic silver to silver salt Remove undecomposed AgBr as soluble silver THIOSULPHATE complex Remove REDUCED silver Answer :C

Discussion

32.	Sodium thiosulphate is used in photography
Answer» To CONVERT metallic SILVER into silver salt AgBr grain is reduced to non-metallic silver To remove reduced silver To remove undercomposed AgBr in the form of `Na_(3)[Ag[S_(2)O_(3))_(2)]` (a complex salt) Solution :Sodium thiosulphates removes the undercompose AgBr in the form of `Na_(3)[Ag(S_(2)O_(3))_(2)]` complex `AgBr +2Na_(2)S_(2)O_(3) to Na_(3) [Ag(S_(2)O_(3))_(2)]+NaBr`

Discussion

33.	Sodium thiosulphate is used in photography beacause of its:
Answer» REDUCING nature Oxidising nature Complex FORMING nature Reaction with light Answer :C

Discussion

34.	Sodium thiosulphate is prepared by :
Answer» BOILING `Na_2SO_3` solution with elemental sulphur in alkaline medium Boiling `Na_2SO_3` solution with elemental sulphur in acidic medium Oxidation of poly sulphides , `Na_2S_3` with air Reduction of bisulphite solution plus `SO_2` with zinc dust Solution :(A)`Na_2SO_3 + S underset(OH^- or H_2O)overset("boiling")toNa_2S_2O_3` (B)`S_2O_3^(2-)` formed in presence of acid precipitates sulphur and liberates `SO_2` gas according to the FOLLOWING reaction . `S_2O_3^(2-)+H^(=)tounderset("DISPROPORTIONATION")(Sdarr`(white) + `SO_2) uarr H_2O` (C )`2Na_2S_3 + 3O_2 underset("air")overset("heating")to2Na_2S_2O_3 + 2S` (D)`2HSO_3^(-)+SO_2overset(Zn)to S_2O_4^(2-)+SO_3^(2-)+H_2O`

Discussion

35.	Sodium thiosulphate is formed when:
Answer» NAOH is NEUTRALIZED by `H_2SO_3` `Na_2S` is BOILED with S `Na_2SO_3` is boiled with S `Na_2SO_3` is boiled with `Na_2S` ANSWER :C

Discussion

36.	Sodium thiosulphate can be prepared by
Answer» Boiling `Na_(2)SO_(3)` solution with sulphur in acidic MEDIUM Boling an aqueous solution of NAOH with sulphur Neutralising `H_(2)SO_(4)` with NaOH Boiling `Na_(2)SO_(3)` with sulphur in alkaline medium Solution :Choice (b) is correct When sulphur is boiled in aqueous NaOH then sodium THIOSULPHATE and sodium sulphide are formed `4S + 6NaOH to Na_2S_2O_(3) + 2Na_(2)S + 3H_(2)O` Choice (d)is also correct becausewhen sulphur is boiled with sodium sulphite, then sodium thiosulphate is formed `Na_(2)SO_(3) + S to Na_(2)S_(2)O_(3)`

Discussion

37.	By which process,Sodium Hydroxide is manufactured ?
Answer»

Discussion

38.	which is most electropositive element in periodic table that is not radioactive :-
Answer» Francium Cesium Barium None of these Answer :B

Discussion

39.	What colour did we observe when Lithium bring near flame ?
Answer» Red Crimson red yellow Violet Answer :B

Discussion

40.	Sodium thiosulfate is a salt of which acid ?
Answer» SOLUTION :Sodium THIOSULFATE is the salt of thiosulfuric ACID-an unstable acid.

Discussion

41.	Sodium sulphite (Na_(2)SO_(3)) is added to meat as a preservative. The presence of Na_(2)SO_(4) can be detected by adding dil. H_(2)SO_(4) when the pungent smelling gas evolved turns the lime water milky. The gas evolved was detected as sulphur dioxide. The SO_(2) " to "SO_(4)^(2-) in titration. SO_(2)+2H_(2)O+I_(2) to 4H^(+)+SO_(4)^(2-)+2I^(-) In order to check the results of titration, excess barium chloride is added to the final solution. The resulting precipitate is collected and weighed. Q.SO_(2) and CO_(2) both lime water milky. Which of the following reagent can be used to distinguish these two gases? (I)K_(2)Cr_(2)O_(7)"/"H_(2)SO_(4)(II)KMnO_(4)"/"H^(+) (III)I_(2) solution
Answer» I, II, III correct I. III only correct II, III only correct III only correct Answer :A

Discussion

42.	Sodium sulphate is soluble in water, while barium sulphate is sparingly soluble because :
Answer» The HYDRATION energy of SODIUM sulphate is more than its LATTICE energy The lattice energy of BARIUM sulphate is less than the hydration energy The lattice energy has no role to PLAY in solubility The hydroation energy of sodium sulphate is less than its lattice energy Answer :A

Discussion

43.	Sodiumsulphiteis used as
Answer» ANTISEPTIC SWEETENING agent antioxidant ANALGESIC and antipyretic Answer :C

Discussion

44.	Sodium sulphite is used in preserving squashes and other mildly acidic foods due ot
Answer» Potassium SALT has preservativeaction Potassium metabisulphite prevents oxidation Potassium metabisulphite is not influcenced by acid Sulphur dioxide and SULPHUROUS acid formed kill BACTERIA and germs Answer :D

Discussion

45.	Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because:
Answer» The hydration energy of sodium sulphate is more than its lattice energy The lattice energy has no ROLE to PLAY in solubility The hydration energy of sodium sulphate is less than its lattice energy None of these Answer :A

Discussion

46.	Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because
Answer» The hydration energy of sodium sulphate is more than its LATTICE energy The lattice energy of barium sulphate is more than its hydration energy The lattice energy has no role to play in solubility The hydration energy of sodium sulphate is less than its lattice energy Solution :`BaSO_(4)` is sparingly soluble in WATER because its hydration energy is LESSER than the lattice energy and thus ions are not SEPARATED from each other. On the contrary in `Na_(2)SO_(4)`, the hydration energy is more than its lattice energy. Thus ions are separated from each other and pass in solution state.

Discussion

47.	Sodium sulphate dissolves in water with evolution of heat. Consider a sturated solution of sodium sulphate.If the temperature is raised, then according to Le-Chatelier principle
Answer» More solid will dissolve Some solid will PRECIPITATE out from the solution The solution will become supersturated Solution CONCENTRATION will remain UNCHANGED Solution :When temperature increases precipitation of SODIUM sulphate takes place. Because reaction is EXOTHERMIC so reverse reaction will take place.

Discussion

48.	Sodium stearate forms associated colloids
Answer» due to ASSOCIATION of Nations due to dissociation of stearate ion due to ORIENTATION of hydrocarbon chain towards CENTRE of the micelle and `COO^(-`) groups towards water due to orientation of `COO^(-)` groups towards center of the micelle and hydrocarbon chain towards water Answer :C

Discussion

49.	Sodium salts of some acids are very useful as food preservatives. Suggest a few such acids.
Answer» SOLUTION :BENZOIC ACID, sorbic acid and PROPANOIC acid.

Discussion

50.	Sodium salts of same acids are very useful as food preservatives. Suggest a few such acids.
Answer» SOLUTION :Sodium SALTS of some acids are very useful as food preservatives. Some examples of such acids are as follows. (i) Sodium benzoate is a COMMON preservatives in acid or acidified foods such as fruits, juices, pickles etc. (II) Sorbic acids is a food additive used predominate in meats, poultry and soft drinks. (iii) Sodium propanoate Na `(C_(2)H_(5)COO)` is used in bakery PRODUCTS as mold inhibitor.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Solid AB has the NaCZ structure. Atom A occupy the corners of the cubic unit cell. If all the face centered atoms along one of the axes are removed, then the resultant stoichio­metry of the solid is

Solid (A) reacts with strong aqueous NaOH liberating a foul smelling gas (B) which spontaneously burn in air giving smoky rings. A and B are respectively

Solid (A) reacts with strong aqueous NaOH liberating a foul smelling gas (B) which spontaneouly burn in air giving smoky rings. A and B are respectively …………… .

Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it ?

Solid A is very hard, insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?

Solid A + H_(2)O rarr (B) (while turbity which redissolves in HCI) Identify D

Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?

Solid A is a very hard electrical insulator in solid as well as in molten state, and melts at extremely high temperature. What type of solid is it ?

Solid A + H_(2)O rarr (B) (while turbity which redissolves in HCI) Identify B

Solid A + H_(2)O rarr (B) (while turbity which dissolves in HCI) Identify C

Solid A + H_(2)O rarr (B) (while turbity whichredissolves in HCI) Identify A

Solid A + H_(2)O rarr (B) (while turbity which dissolves in HCI) Identify E

Solder in an alloy of :

Solar ultraviolet radiation is absorbed by :

Soil containing both Al and Fe is called

Sol of egg albumin is prepared by

Sol particles of ferric hydroxide (I) and arsenlous sulphate (II) are positively and negatively charged respectively . Which of the following are correct-

Soilsalinity can be measured by

Softerning of lead means:

Soft heavy metal melts at 30^(@)C and is used in making heat sensitive thermometers the metal is

Soft soaps are

Soft d-block elements occurs as

Soft drink and baby-feeding bottles are generally made of:

Soft drinks and baby feeding bottles are generally made up of

Soft and pliable steel is obtained by :

Sodium when heated in a current of dry ammonia gives

Sodium zeolite is :

Sodium vapour is paramagnetic, but cations of sodium are diamagnetic, while vapour magnesium as well as cations of magnesium are diamagnetic. Explain.

Sodium thiosulphate, Na_(2)S_(2)O_(3)*5H_(2)O is used in photography to:

Sodium thiosulphate is used to remove the unexposed AgBr from photographic films by forming a complex. In this complex of silver, the coordination number ofsilver is:

Sodium thiosulphate, Na_2S_2O_3.5H_2O is used in photography to:

Sodium thiosulphate is used in photography

Sodium thiosulphate is used in photography beacause of its:

Sodium thiosulphate is prepared by :

Sodium thiosulphate is formed when:

Sodium thiosulphate can be prepared by

By which process,Sodium Hydroxide is manufactured ?

which is most electropositive element in periodic table that is not radioactive :-

What colour did we observe when Lithium bring near flame ?

Sodium thiosulfate is a salt of which acid ?

Sodium sulphate is soluble in water, while barium sulphate is sparingly soluble because :

Sodiumsulphiteis used as

Sodium sulphite is used in preserving squashes and other mildly acidic foods due ot

Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because:

Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because

Sodium sulphate dissolves in water with evolution of heat. Consider a sturated solution of sodium sulphate.If the temperature is raised, then according to Le-Chatelier principle

Sodium stearate forms associated colloids

Sodium salts of some acids are very useful as food preservatives. Suggest a few such acids.

Sodium salts of same acids are very useful as food preservatives. Suggest a few such acids.

Solid AB has the NaCZ structure. Atom A occupy the corners of the cubic unit cell. If all the face centered atoms along one of the axes are removed, then the resultant stoichiometry of the solid is