94420 + Interview Questions in Chemistry in Class 12

1.	Second electron gain enthalpy:
Answer» is ALWAYS negative is always POSITIVE can be positive or negative is always zero Answer :B

Discussion

2.	seaweed contains iodine upto
Answer» `0.5%` `6%` `0.60%` `0.05%` Solution :Occurrence of `I_2`- SEE WEEDS contains `I_2` upto 0.5%

Discussion

3.	Sea weed is employed as a source of manufacture of
Answer» F <BR>l Br CL Answer :B

Discussion

4.	Sea water contains small quantities of MgCl_(2) and MgS_(4) Sea water is treated with slaked limeto precipitate the dissolved salty as Mg(OH)_(2) The Mg(OH)_(2) is dissolved in a little quantity of HCI and MgCl_(2)6H_(2)O is crystallised from solution. The hydrated MgCl_(2) is heated in a current of dry HCl gas to get anhydrous MgCl_(2) Pused anhydrous MgCl_(2) is subjected to electrolysis. Magnesium deposited at cathode. In the Hanging method magnesia is a reved by using
Answer» Si `CaC_(2)` `FESI` COKE Solution :In Hamsging process magnesia (MGO) is reduced by coke

Discussion

5.	Sea water contains small quantities of MgCl_(2) and MgS_(4) Sea water is treated with slaked limeto precipitate the dissolved salty as Mg(OH)_(2) The Mg(OH)_(2) is dissolved in a little quantity of HCI and MgCl_(2)6H_(2)O is crystallised from solution. The hydrated MgCl_(2) is heated in a current of dry HCl gas to get anhydrous MgCl_(2) Pused anhydrous MgCl_(2) is subjected to electrolysis. Magnesium deposited at cathode. Magnesium metal is extracted from
Answer» Carnalite Magnesite Sea water All of these Solution :Mg is the METAL present in the ORES CARNALLITE, Magnesite and sea water as SULPHATES and chlorides

Discussion

6.	Sea water is converted into fresh water based upon the phenomenon of
Answer» Diffusion Osmosis Plasmolysis Reverse osmosis. Answer :D

Discussion

7.	Sea water contains small quantities of MgCl_(2) and MgS_(4) Sea water is treated with slaked limeto precipitate the dissolved salty as Mg(OH)_(2) The Mg(OH)_(2) is dissolved in a little quantity of HCI and MgCl_(2)6H_(2)O is crystallised from solution. The hydrated MgCl_(2) is heated in a current of dry HCl gas to get anhydrous MgCl_(2) Pused anhydrous MgCl_(2) is subjected to electrolysis. Magnesium deposited at cathode. Which of the following process is used in the extractive metallurgy of magnesium
Answer» Fused SALT electrolysis Self reduction Aqueous SOLUTION electrolysis Thermitt reduction Solution :Fused salt electrolysis is the PROCESS can be USED for the extraction of more electro positive metals like MG.

Discussion

8.	Sea water contains 1272 g of Mg^(2+) per metric ton (1 mega gram). How much of slaked lime must be added to 1.0 metric ton of sea water to precipitate all the Mg^(2+) ion. (give approx value in kg).
Answer» Solution :4 KG (approx) `Mg^(2+) + Ca (OH)_(2) darr + Ca^(2+)` 74 gm In sea water 24 gm 24 gm of `Mg^(2+) -= 74 G Ca(OH)_(2)` `therefore""1272 g Mg^(@+) -= (74)/(24) xx 1272 = 3922 g` `= 3.922 kg ~~ "4 kg of Ca"(OH)_(2)`

Discussion

9.	Sea water contains Magnesium in the form of
Answer» CARBONATE CHLORIDE Suphate Both 2 & 3 Answer :D

Discussion

10.	Sea water contains 1.15 xx 10^(4) ppm of Na^(+) and 3.84 xx 10^(4)ppm of SO_(4)^(2-). Calculate sum of molar concentration of Na^(+) and SO_(4)^(2-). [Given : density of Sea water is 1 gm/ml ]
Answer» Solution :`NA^(+) rArr 1.15 xx 10^(4) gm Na^(+)` in `10^(6)` gm of solution `SO_(4)^(2) rArr 3.84 xx 10^(4) gm SO_(4)^(2-)` in `10^(6)` gm of solution `M_(Na^(+)) = (((1.15 xx 10^(4))/(23)))/(10^(6)) xx 1000 = 0.5` `M_(SO_(4)^(2-)) = (((3.84 xx 10^(4))/(96)))/(10^(6)) xx 1000 = 0.4` `M_("TOTAL") = M_(Na^(+)) + M_(SO_(4)^(2-))` `= 0.5 + 0.4 = 0.9` 9

Discussion

11.	Sea is the greatest source of some halogens. Comment.
Answer» Solution :Sea WATER has chlorides, bromides and iodides of potassium, SODIUM, magnesium and CALCIUM. However, Sodium chloride is present in maximum making sea water saline. VARIOUS sea WEEDS contain upto 0.5% iodine.

Discussion

12.	Sea foods are best preserved by which of the following method ?
Answer» Irradiation Curing Pasteurization Dehydration Answer :A

Discussion

13.	Sea is the greatest source of halogens. Comment.
Answer» Solution :Sea water CONTAINS chlorides, bromides and iodides of SODIUM, potassium, magnesium and calcium, but mainly sodium CHLORIDE (2.5% by mass). Dried up sea beds CONTAIN sodium chloride and carnallite, `KCl.MgCl_(2).6H_(2)O`. Certain seaweeds contain upto 0.5% of iodine as sodium iodide and CHILE saltpetre `(NaNO_(3))` contains upto 0.2% of sodium iodate. Thus, sea is the greatest source of halogens.

Discussion

14.	Sea foods are best preserved by adding
Answer» NaCI sugars `SO^(2)` BHA Answer :A

Discussion

15.	Sea diver, for breathing inside sea use the mixture of belium and oxygen. Why ?
Answer» SOLUTION :For ANSWER CONSULT SECTION -3.

Discussion

16.	Sea divers go deep in the sea water with a mixture of which of the following gases?
Answer» `O_2`and He `O_2` and AR `O_2` and `CO_2` `CO_2` and Ar Answer :A

Discussion

17.	Sea divers for breathing inside sea use a mixture of O_(2) and inert gas............... .
Answer» SOLUTION :HELIUM (He)

Discussion

18.	Sc (Z=21)is a transitionelementbut Zinc(Z=30)is notbecause
Answer» both `Sc^(3+)` and `Zn^(2+)` ions are colourless and form white compounds In case of Sc, 3D orbital are partially filled but in Zn these are completely filled LAST electron as assumed to be ADDED to 4s level in case of zinc both Sc and Zn do not exhibit variable oxidation states Answer :B

Discussion

19.	Scurvy is caused due to deficiency of
Answer» VITAMIN A Vitamin C Cellulose Vitamin D Answer :B

Discussion

20.	Scurvy is caused due to
Answer» Vit-A vit-K vit-E vit-C Answer :D

Discussion

21.	Scurvy is caused due to deficiency of :
Answer» VITAMIN `B_1` Vitamin `B_2` ASCORBIC acid Glutamic acid Answer :C

Discussion

22.	Screening effect is not observed in :-
Answer» `He^(+)` `LI^(+2)` `Be^(+3)` All of the above Answer :D

Discussion

23.	Scouring soaps and soap powders contain soap along with
Answer» Lime Powdered PUMICE `Al_2(SO_4)_3` All ANSWER :B

Discussion

24.	SCl_(4) on hydrolysis gives
Answer» `H_(2)SO_(4),HCl` `H_(2)S, HCLO` `SOCl_(2), HCl` `H_(2)SO_(3), HCl` Answer :D

Discussion

25.	SCl_(4) on hydrolysis gives:
Answer» `H_(2)SO_(3)` `H_(2)SO_(4)` `H_(2)S_(2)O_(7)` `H_(2)S_(2)O_(8)` ANSWER :A

Discussion

26.	Scientist who explained the structures and isomerism in the complex compound was:
Answer» Sidgwick Pauling Powell Werner Answer :D

Discussion

27.	The scientist who explained the structure of co- ordination complexes is
Answer» Sidgwick Pauling Powell Werner Answer :D

Discussion

28.	SCI_(6) is not known but SF_(6) is known. Give reasons.
Answer» Solution :Fluorine is a much stronger oxidising agent than chlorine, therefore, it can EASILY oxidise sulphur to its maximum oxidation state of+6 and hence FRMS `SF_(6)`. Chlorine, on the other HAND, being a WEAKER oxidising agent can oxidise sulphur at the maximum to its +4 oxidation state and hence can form `SCI_(4)` but not `SCI_(6)`.

Discussion

29.	Scientfic aspect of fermentation was first studied by :
Answer» Pasteur Brot Buchner Liebig Answer :C

Discussion

30.	Schweitzer's reagent used for dissolving cellulose in the manufacture of artificial silk is
Answer» `CuSO_(4).5H_(2)O` `CuI` `[Cu(NH_(3))_(4)]SO_(4)` `Cu(CH_(3)COO)_(2).Cu(OH)_(2)` Solution :`[Cu(NH_(3))_(4)] SO_(4)` is schweitzer's reagent used for MANUFACTURE of artificial silk.

Discussion

31.	Schweitzer's reagent used for dissolvingcellulose in the manufacture of artificial silk is :
Answer» `CuSO_4."5" H_2O` `CUI` `[Cu(NH_3)_4(H_2O)_2](OH)_2` `Cu(CH_3COO)_2Cu(OH)_2` Answer :C

Discussion

32.	Schweitzer reagent is:
Answer» `[Cu(NH_3)_4(H_2O)_2](OH)_2` `[Ag(NH_3)_2]Cl` `Cu(NH_3)_2Cl` `K_4Fe(CN_6)` Answer :A

Discussion

33.	Schottky defects and Frenkel defects are two stoichiometric defects shown by crystals.Classify the following crystals into those showing Schottky defects and Frenkel defects: NaCl, AgCl, CsCl, CdCl_2
Answer» SOLUTION :Schottchy DEFECT- NACL,CSCL FRENKEL defect-AgCl,`CdCl_c`

Discussion

34.	Schottky defects and frenkel defects are two stoichiometric defects shown by crystals. Classify the following crystals into those showing schottky defects and frenkel defects NaCl,AgCl,CsCl,CdCl_2 name a crytal showing both schottky defects and frenkel defects.
Answer» Solution :Schottky DEFECT: NaCl, CSCL, Frenkel DEFECTS: AgCl, `CdCl_2`

Discussion

35.	Schottky defect lowers the density of ionic crystals while Frenkel defect does not. Why?
Answer» SOLUTION :In Schottky defect, certain cations and ANIONS are MISSING from LATTICE site resulting in decrease in mass per unit volume, i.e., density. On the other hand, in Frenkel defect, the ions do not leave the lattice but they simply change their positions from lattice points to the interstitial spaces. As a result, the density of the crystal does not change.

Discussion

36.	Schottky defect is observed in crystals when………… .
Answer» some cations MOVE from their lattice site to interstitial sites. equal number of cations and anions are missing from the lattice. some lattice sites are occupied by electrons. some impurity is PRESENT in the lattice. SOLUTION :The ionic CRYSTALS with nearly same sized cations and anions show Schottky defects where equal number of cations and anions are missing from lattice site to maintain ELECTRICAL neutrality.

Discussion

37.	Schottky defect is observed in crystals when
Answer» some CATIONS move from their lattice SITE to interstitial SITES equal NUMBER of cations and anions are MISSING from the lattice some lattice sites are occupied by electrons some impurity is present in the lattice Solution :equal number of cations and anions are missing from the lattice

Discussion

38.	Schottky defect is likely to be found in :
Answer» Agl NaCl ZnS ZnO Solution :Due to small DIFFERENCE in SIZE of `Na^(+)` and `Cl^(-)`ions and HIGH coordination NUMBER, NaCl has schottky DEFECTS .

Discussion

39.	Schottkydefect is likelyto be found in
Answer» AgI NaCI ZnS ZnO Answer :B

Discussion

40.	Schottky defect is noticed is:
Answer» NaCI KCI CsCI All Answer :D

Discussion

41.	Schottky defect in crystals is observed when
Answer» UNEQUAL NUMBER of CATIONS and anions are missing from the lattice Equal number of cations and anions are missing from the lattice An ION leaves its normal site and occupies an interstitial cells Density of the crystal is increased Answer :B

Discussion

42.	Schottky defect in a crystal is observed when………………..
Answer» UNEQUAL number of anions and anions are missing from the LATTICE equal number of anions and anions are missing from the lattice an ion leaves its NORMAL site and occupies an INTERSTITIAL site no ion is missing from its lattice. Solution :equal number of anions and anions are missing from the lattice

Discussion

43.	Schottky defect in a crystal is observed when,
Answer» UNEQUAL number of cations and ANIONS are MISSING from the lattice equal number ofcations and anions are missing from the lattice an ion leaves its normal site and occupiesan interstitital site density of the crystal is increased Answer :B

Discussion

44.	Schottky defect causes
Answer» increase in the DENISTY of SOLID DECREASE in the density of solid no changein the density of solid decrease in the conductivity of solid Answer :B

Discussion

45.	Schottky and frenkel defects are stoichiometric defects. Write any two differences between schottky defects and frenkel defects.
Answer» SOLUTION :

Discussion

46.	Schiff's regeant gives colour with
Answer» Alcohols Acetaldehyde Acetone Mesitylene chloride Answer :B

Discussion

47.	Schiff's reagent is obtained by passing
Answer» `SO_(2)` GAS in AQ. Solution of ROSANILINE `NO_(2)` gas in aq. Solution of rosaniline `O_(2)` gas in aq. Solution of rosaniline `CO_(2)` gas in aq. Sol. of rosaniline Answer :A

Discussion

48.	Schiff.s reagent is :
Answer» Magenta SOLUTION decolourised with SULPHURIC acid Magenta solution decolourised with chlorine Ammoniacal COBALT CHLORIDE solution Ammoniacal manganese sulphate solution ANSWER :A

Discussion

49.	Which colour of Schiff's reagent is restored by aldehydes.
Answer» MAGENTA SOLUTION decolourised with SULPHURIC acid Magenta solution decolourised with chlorine Ammoniacal COBALT chloride solution Ammoniacal manganese SULPHATE solution Answer :A

Discussion

50.	Schiff's reagent is __________.
Answer» `CuSO_(4)` solution + alkaline POTASSIUM tartarate solution ammoniacal SILVER nitrate solution p-rosaaniline hydrochloride solution +`SO_(2)` potassium dichromate in dil. `H_(2)SO_(4)` ANSWER :C

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Second electron gain enthalpy:

seaweed contains iodine upto

Sea weed is employed as a source of manufacture of

Sea water is converted into fresh water based upon the phenomenon of

Sea water contains 1272 g of Mg^(2+) per metric ton (1 mega gram). How much of slaked lime must be added to 1.0 metric ton of sea water to precipitate all the Mg^(2+) ion. (give approx value in kg).

Sea water contains Magnesium in the form of

Sea water contains 1.15 xx 10^(4) ppm of Na^(+) and 3.84 xx 10^(4)ppm of SO_(4)^(2-). Calculate sum of molar concentration of Na^(+) and SO_(4)^(2-). [Given : density of Sea water is 1 gm/ml ]

Sea is the greatest source of some halogens. Comment.

Sea foods are best preserved by which of the following method ?

Sea is the greatest source of halogens. Comment.

Sea foods are best preserved by adding

Sea diver, for breathing inside sea use the mixture of belium and oxygen. Why ?

Sea divers go deep in the sea water with a mixture of which of the following gases?

Sea divers for breathing inside sea use a mixture of O_(2) and inert gas............... .

Sc (Z=21)is a transitionelementbut Zinc(Z=30)is notbecause

Scurvy is caused due to deficiency of

Scurvy is caused due to

Scurvy is caused due to deficiency of :

Screening effect is not observed in :-

Scouring soaps and soap powders contain soap along with

SCl_(4) on hydrolysis gives

SCl_(4) on hydrolysis gives:

Scientist who explained the structures and isomerism in the complex compound was:

The scientist who explained the structure of co- ordination complexes is

SCI_(6) is not known but SF_(6) is known. Give reasons.

Scientfic aspect of fermentation was first studied by :

Schweitzer's reagent used for dissolving cellulose in the manufacture of artificial silk is

Schweitzer's reagent used for dissolvingcellulose in the manufacture of artificial silk is :

Schweitzer reagent is:

Schottky defects and Frenkel defects are two stoichiometric defects shown by crystals.Classify the following crystals into those showing Schottky defects and Frenkel defects: NaCl, AgCl, CsCl, CdCl_2

Schottky defects and frenkel defects are two stoichiometric defects shown by crystals. Classify the following crystals into those showing schottky defects and frenkel defects NaCl,AgCl,CsCl,CdCl_2 name a crytal showing both schottky defects and frenkel defects.

Schottky defect lowers the density of ionic crystals while Frenkel defect does not. Why?

Schottky defect is observed in crystals when………… .

Schottky defect is observed in crystals when

Schottky defect is likely to be found in :

Schottkydefect is likelyto be found in

Schottky defect is noticed is:

Schottky defect in crystals is observed when

Schottky defect in a crystal is observed when………………..

Schottky defect in a crystal is observed when,

Schottky defect causes

Schottky and frenkel defects are stoichiometric defects. Write any two differences between schottky defects and frenkel defects.

Schiff's regeant gives colour with

Schiff's reagent is obtained by passing

Schiff.s reagent is :

Which colour of Schiff's reagent is restored by aldehydes.

Schiff's reagent is __________.