94420 + Interview Questions in Chemistry in Class 12

1.	CompareLantanides andactinides.
Answer» SOLUTION :

Discussion

2.	Compareenolpercent (I ) CH_(3) - overset(O) overset(\|\|) (C ) - CH_(3) (ii )CD_(3) - overset(O) overset(\|\|)(C )- CH_(3) (iii) CH_(3)- overset(O) overset(\|\|) (C ) - CD_(3)
Answer» Solution :As we know `C-D gt C- H` (Bondstrength ) `rArr C- D ` willnotbreakeasily `rArr ` COMPOUND willhavelesstendency to comeintoin ENOL formas C-Dbondbreakingis oneof the stepforconversionof ketointoend. `rArr `enolpercentwillbe LESS `rArr (I ) gt (II) gt (iii)` (enol CONTENT )

Discussion

3.	Compare dipole moment of the following CH_(3)-CH_(2)-C=CH, CH_(3)-C=C-CH_(3)
Answer» ANSWER :(A) `I GT II`(B)`ii gt i` (C ) `I gt ii`

Discussion

4.	Compare and contrast the “shock therapy “of the USSR with “’the open door’ policy of China.
Answer» Solution :Compare/ Contrast China a. The Chinese did not go for shock therapy but opened their economy step by step. b. The privatization of agriculture began in 1982 and was followed by the privatization of industry in 1998. c. Trade barriers were eliminated only in special economic zones (SEZS) where foreign investors could set up enterprises. d. In China, the state played and continues to play a central role in setting up a MARKET economy USSR, a. Shock therapyGorbachev ahead of his TIMES with Perestroika and Demokratizatsiya and Glasnost b. Sudden shift to Liberal CAPITALISM collapse of Economy. Rise of Mafia - GARAGE sale of Industries.

Discussion

5.	Commonly used moth repllent is
Answer» P.D.C.B. D.D.T. B.H.C. E.D.B. Solution :P.D.C.B (p-Dichlorobenzene) is a COMMON MOTH REPELLENT.

Discussion

6.	Commonly used antiseptic 'Dettol' is a mixture of:
Answer» o-cresol + terpeneol PHENOL + terpeneol CHLOROXYLENOL + terpeneol o-chlorophenol + terpeneol. Answer :C

Discussion

7.	Commonly used laboratory desiccant is:
Answer» CALCIUM chloride Sodium carbonate Sodium chloride Potassium nitrate Answer :A

Discussion

8.	Commonly used antiseptic 'Dettol' is a mixture of
Answer» o-chlorophenozylenol + terpeneol o-cresol + terpeneol phenol+ terpeneol CHLOROXYLENOL + terpeneol Solution :The MIXTURE of chloroxylenol and terpenol is DETTOL which is USED as ANTISEPTIC

Discussion

9.	Commonly used antiseptic 'dettol' is a mixture of ....
Answer» O - CHLORO phenozylenol + terpeneol O-cresol + terpenol PHENOL + terpeneol CHLOROXYLENOL + terpeneol Solution :chloroxylenol + terpeneol

Discussion

10.	Common table sugar is a disachharide of
Answer» GLUCOSE and fructose glucose and galactose fructose and galactose maltose and lactose Answer :A

Discussion

11.	Common table sugar is more formally described as
Answer» Glucose Lactose Maltose Sucrose Answer :D

Discussion

12.	Common table salt becomes moist and does not pour easily in rainy seasons because:
Answer» It CONTAINS MAGNESIUM chloride It contains magnesium carbonate It MELTS slightly in rainy season Sodium Chloride is hygroscopic Answer :A

Discussion

13.	Common table salt becomes moist and does not pour easily in rainy season because
Answer» it CONTAINS magnesium chloride. it contains magnesium carbonate. it metals slightly in RAINY season. sodium chloride is hygroscopic. Solution :The table SALT contains the impurity of `MgCl_(2)` which is hygroscopic in nature. Pure `NACL` never moists.

Discussion

14.	Common sugar is
Answer» glucose fructose sucrose both 'a' and 'b' Answer :C

Discussion

15.	Common salt obtained from sea water contains95% NaCl by mass. The approximate number of molecules present in 10g of the salt is
Answer» `10^21` `10^22` `10^23` `10^24` SOLUTION :NUMBER of molecules in 10 g of NaClhaving 95% purity ` = (6.023 XX 10^23)/(58.5) xx 10 xx 95/100` `= 9.78 xx 10^22 = 10^23`

Discussion

16.	Common salt obtained from sea-water contains 95% NaCl by mass. The approximate number of molecules present in 10g salt is:
Answer» `10^(21)` `10^(22)` `10^(23)` `10^(24)` Solution :Mass of NaCl in 10G salt`=10xx(95)/(100)=9.5g` NUMBER of MOLECULES of `NaCl=(9.5)/(58.5)xx6.023xx10^(23)` `=9.78xx10^(22)=10^(23)`

Discussion

17.	Common salt brings about preservation of pickles by phenomenon of______.
Answer» DIFFUSION osmosis dissolution hydrolysis Answer :B

Discussion

18.	Common reducing reactions of monosaccharides are due to
Answer» Their cyclic structures The PRESENCE of at least one hydroxyl GROUP The presence of more than one hydroxyl group The presence of a carbonyl group, USUALLY on the C-1 CARBON atom Answer :D

Discussion

19.	Common oxidation state of element of atomic number 47 is:
Answer» `+1` `+2` `+3` `+4` ANSWER :A

Discussion

20.	Common name of Propane 2 - ol is ….
Answer» Propanol Butanol ISOPROPYL ALCOHOL None of these Solution :Isopropyl alcohol

Discussion

21.	Common name of pentanal is -----------.
Answer» ANSWER :T

Discussion

22.	Common name of HOOC-(CH_(2))_(4)-COOH is
Answer» GLUTARIC acid. adipic acid. succinic acid. malonic acid. Answer :B

Discussion

23.	Common name of ethoxybenzene, is anisole
Answer» ANSWER :F

Discussion

24.	Common name of DDT is
Answer» <P>p,p DICHLORO diphenyl tetrachlorethane p,p-dichlorodiphenyl TRICHLORO ethane p,p- dichlorodipheynl TETRACHLORO methane p,p-dichlorodiphenyl trichloro methanae Answer :B

Discussion

25.	common name of chloroethene is allyl chloride.
Answer»

Discussion

26.	Common monomer n melamine formaldehyde and Bakelite
Answer» Formaldehyde PHENOL Melomine ETHYLENE GLYCOL ANSWER :B

Discussion

27.	Common monomer in glyptal and terylene is
Answer» ETHYLENE GLYCOL PHTHALIC ACID Phenol Formaldehyde Answer :A

Discussion

28.	Common impurities present is Bauxite are :
Answer» `CUO` `ZNO` `Fe_2O_3` NONE of these ANSWER :C

Discussion

29.	Common impurities present in bauxite are.....
Answer» CuO ZnO `Fe_2O_3` `SiO_2` SOLUTION :`Fe_2O_3` and `SiO_2` are IMPURITIES present in BAUXITE. `SiO_2` is REMOVED as SOLUBLE silicates while `Fe_2O_3` is precipitated as hydroxides.

Discussion

30.	Commonimpuritiespresentin bauxite are .........
Answer» CUO ZNO ` Fe_2 O_3` ` SiO_2 ` ANSWER :C::D

Discussion

31.	Commericial sample of H_(2)O_(2)is labeled as 10 V. Its % strength is nearly
Answer» 3 6 9 12 Solution :10 V (10 volume) `H_(2)O_(2)` means that 1 mL of `H_(2)O_(2)` solution will produce 10 mL of `O_(2)` at STP. Now, decomposition of `H_(2)O_(2)` is as below: `underset((2xx34)g)(2H_(2)O_(2))rarr 2H_(2)O+underset("22400 mL (at STP)")(O_(2))` `=68g` `THEREFORE"22400 mL of "O_(2)" is OBTAINED from 68 g of "H_(2)O_(2)` `therefore"10 mL of "O_(2)" is obtained from "(68)/(22400)xx"10 g of "H_(2)O_(2)` `=0.03036g" of "H_(2)O_(2)` but this 10 mL of `O_(2)` corresponds to 0.03 g of `H_(2)O_(2)` solution APPROXIMATELY. Therefore, 1 mL of `H_(2)O_(2)` solution CONTAINS 0.03 g of `H_(2)O_(2)` `therefore"100 mL of "H_(2)O_(2)" solution contains 3 g of "H_(2)O_(2)` `therefore"% strength is 3."`

Discussion

32.	Commercially nitrogen is prepared from
Answer» by passing VAPOURS of `HNO_(3)` on HEATED copper thermal decomposition of BARIUM azide liquification of air oxidation of `NH_3` Answer :C

Discussion

33.	Commercially methanol is prepared by
Answer» Reduction of CO in presence of `ZnO.Cr_(2)O_(3)` Methane reacts with water VAPOURS at `900^(@)C` in presence of NI catalyst Reduction of HCHO by`LiAlH_(4)` Reduction of HCHO by AQUEOUS NaOH Solution :`CO+H_(2) underset(573K,200 "atm")OVERSET(CuO-ZnO-Cr_(2)O_(3))to underset("Methanol")(CH_(3)OH)`

Discussion

34.	Commercially important ore of copper is its
Answer» OXIDE ORE sulphide ore sulphate ore SILICATE ore ANSWER :B

Discussion

35.	Commercially important ore of lead is :
Answer» Haematite Sphalerite Siderite Galena Answer :D

Discussion

36.	Commercially available cone. HCI contains 38% HCI by mass density of 1.19 g cm^(3). Calculate the molarity of this solution.
Answer» Solution :Mass of HCI in solution = 38 G , Mass os SOUTION = 100 g DENSITY of solution `=1.19" g mol"^(-3)` `"Volume of 100 g of solution"=((100g))/((1.19cm^(-3))=84 cm^(3)`. `"Molarity of solution (M)"=("Mass of HCI/Molar mass")/("Volume of solution in dm"^(-3))=((38.0g)//(36.5" g mol"^(-1)))/(84//1000(DM^(3)))=12.39 m`.

Discussion

37.	Commercially available concentrated hydrochloric acid contains 38% HCl by mass. (a) What is the molarity of this solution ? The density is 1.19 g cm^(-3) (b) What volume of concentrated hydrochloric acid is required to make 1.00 L of 0.10 M HCl ?
Answer» SOLUTION :CALCULATION of molarity. `38%` HCL by mass means that 38 g of HCl are present in 100 g of the solution. `"Volume of 100 g of the solution"=("Mass ")/("Density")=(100g)/(1.19"g cm"^(-3))=84.03cm^(3)=0.0840L` Molar mass of HCl = `36.5"g mol"^(-1)` `therefore"38 g HCl"=(38)/(36.5)"moles"=1.04" moles"` `"Molarity of solution "=(1.04"moles")/(0.0840L)=12.38"mol L"^(-2)`, i.e., Molarity of the solution = 12.38 M (b) Calculation of volume of conc. HCl for 1.00 L of 0.10 M HCl. Applying molarity equaton, we have `{:(M_(1)xxV_(1),=,""M_(2)xxV_(2)),("(conc. HCl)",,"(1.0 L of 0.10 M HCl)"),(12.38xxV_(1),=,""0.10xx1.0):}` `"or"V_(1)=(0.1)/(12.38)L=(0.1)/(12.38)xx1000cm^(3)=8.1cm^(3)`

Discussion

38.	Commercially available concentrated HCIcontains 38.0% HCl by mass (density = 1.19 g mL^(-1)). The molarity of the solution is
Answer» 10.40 M 5.70 M 12.38 M 13.46 M Solution :38 g of HCl is present in 100 g of solution Vol. of solution ` = (100)/(1.19)` MOLARITY ` = ( (38)/(36.5) XX 1000)/( (100)/(1.19) ) = 12.28M `

Discussion

39.	CommerciallyavailableconcentratedHC1 isand aqueoussolutioncontaining38%HC1by mass.Ifit densityis 1.1 g cm^(-3) (a) Whatis the molarityof the HC1solutionand ( b)molefractions of HC1 andH_(2)O
Answer» SOLUTION :(a)11.45mol `DM^(-3)` or 11.45 M (B) Molefractionof HC1 =0.232 Molefractionof `H_(2) O= 0.768`

Discussion

40.	Commercially available conc. HCl contains 38% HCl by mass and has a density 1.19 g cm""^(-3). Calculate the molarity of this HCI.
Answer» Solution :38% HCl by mass CONTAINS 38 g of HCl in 100 g of solution. Density =`("mass")/(" Volume")` `1.19=(100 )/("volume")` `therefore `Volume of 100 g of solution`= (100 )/(1.19 )`ml. `therefore `STRENGTH of solution `= (38 )/((100)/(1.19 ))xx 1000` `=(38 xx 1.19 xx 1000 )/(100 ) gL^(-1)` MOLECULAR mass of HCI` = 36.5` `therefore `MOLARITY of HCl `= (38 xx 1.19 xx 1000)/(100 xx36.5)` `=( 38 xx 11.9 )/( 36.5 ) =12.39`

Discussion

41.	Commercially, ammonia (NH_(3)) is produced from nitrogen (N_(2)) and hydrogen (H_(2)) using the Haber process N_(2)(g) + 3H_(2) ( g) rarr 2NH_(3)(g) This reaction is exothermic. Which of the following would increase the amount of NH_(3) obtained (i.e. maximize the yield of NH_(3)) at equilibrium ? (i) Decrease the pressure(ii) Increase the temperature (iii) Increase the concentration of N_(2)(iv) Increase the concentration of NH_(3) ( v ) Decrease the concentration of H_(2)
Answer» I,II,IV and V I and III II and III III only ANSWER :D

Discussion

42.	Commercial name 1, 1, 2, 2-tetrachloro-ethane is-.
Answer» ANSWER :WESTRON

Discussion

43.	Commercial detergents contain mainly :
Answer» `RONA` RCOONA `ROSO_3Na` `ROCH_2CHORCH_2OR` ANSWER :C

Discussion

44.	Commercial alcohol is made unfit for drinking by adding
Answer» METHYL alcohol Antimony OXIDE and acetic acid Morphine and ADIPIC acid Snake POISON and malonic acid Answer :A

Discussion

45.	Comment on the statement that the element of the first transition series possess many properties different those of heavier transition elements.
Answer» Solution :The given statement is true as explained below `:` (i) ATOMIC radii of the heavier transition elements ( 4d and 5d series ) are larger than those of the corresponding elements of the FIRST transitionseries though those of 4d and 5d series are very CLOSE to each other. (ii) For first transition series, `+2` and `+3` oxidationstates are more common whereas for heavier transition elements, higher oxidation states are more common( as DISCUSSED in Question) (iii) Melting and boiling POINTS of heavier transition elements are greater thanthose of the first transition series due tostronger intermetallic bonding ( M-M bonding) . (iv) Ionization enthalpiesof 5d series are higher than the corresponding elements of 3d and 4d series. (vi ) The elements of the firsttransition series form low spin or high spin complexesdepending upon the strength of the ligand field.However, the heavier transition elements form low spin complexes irrespective of the strength of the ligand field.

Discussion

46.	Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.
Answer» Solution :The give statement in true as explained below: (a). Atomic radii of the heavier transition elements `(4d` and `5d` SERIES) are larger than those of the CORRESPONDING elements of the first transition series though those of `4d` and `5d` series are very close to each other. (b). Melting and boiling points of hevier transition elements are GREATER than those of the first transition series due to STRONGER entermetallic bonding. (c). Enthalpies of ATOMISATION of `4d` and `5d` series are higher than the corresponding elementsof the rirst series. (d). Inisation enthalpies of `5d` series are higher than the corresponding elements of `3d` and `4d` series.

Discussion

47.	Comment on the statement that "colloid is not a substance but state of a substance".
Answer» Solution :The given statement is true . This is because the statement may exist as a colloid under certain conditions and as a crystalloid under certain other conditions . E.g., NACL in WATER behaves as a crystalloid while in benzene , behaves as a colloid (CALLED associated colloid ). It is the size of the particles while MATTERS i.e., the state in which the substance exist . If the size of the particles lies in the range 1 nm to 100 nm it is in the colloid state.

Discussion

48.	Comment on the statement that elements of the first transition series posses many properties different form those of heavier transition elements.
Answer» Solution :The heavier transition elements belong to fourth (4d), fifth (5d) and sixth (6d) transition series. Their properties are expected to be different from the elements belonging to the first (3d) series due to the following REASONS : (i) Atomic radii of heavier transition elements (4d- and 5d-series) are larger than those of the corresponding elements of the first transition series though those of 4d- and 5d-series are very close to each other. (ii) Ionization ENTHALPIES of 5d-series are HIGHER than the corresponding elements of 3d- and 4d-series. (iii) Enthalpies of atomisation of 4d- and 5d-series are higher than the corresponding elements of the first series. (iv) MELTING and boiling points of heavier transition elements are greater than those of the first transition series due to stronger inter-metallic BONDING.

Discussion

49.	Comment on the statement that "Colloid is not a substance but state of a substance,"
Answer» Solution :The give statement is true. This is because the same substance may exist as a colloid unde certain conditions and as a crystalloid under certain other conditions. For example, NaCl in water behaves as a crystalloid while in BENZENE, it behaves as a colloids. Similarly, dilute SOAP solution behaves like a crystalloid while concentrated solution behaves as a colloid (CALLED associated colloid). It is the SIZE of the particles which matters, i.e., the state in which the substance exists. If the size of the particles lies in the RANGE 1 nm to 100 nm, it is in the colloidal state.

Discussion

50.	Comment on the statement that "colloid is not a substance but a state of substance".
Answer» SOLUTION :"Colloids is not a substance but a state of substance" is a true statement. Because there are some substances which are crystalloid under certain conditions but colloid under the other, e.g., NACL is such substance which is called a crystalloid and behaves as a crystalloid in aqueous medium. But when MIXED with benzene, it behaves as colloids. So, the above statement is correct. Moreover, the DIAMETER of COLLOIDAL particles range from 1 to 1000 nm. If particle diameter is lesser than 1 nm, the solution is true solution and if it is more than 1000 nm, the solution is a suspension. The colloidal state is an intermediate state between these two.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

CompareLantanides andactinides.

Compareenolpercent (I ) CH_(3) - overset(O) overset(||) (C ) - CH_(3) (ii )CD_(3) - overset(O) overset(||)(C )- CH_(3) (iii) CH_(3)- overset(O) overset(||) (C ) - CD_(3)

Compare dipole moment of the following CH_(3)-CH_(2)-C=CH, CH_(3)-C=C-CH_(3)

Compare and contrast the “shock therapy “of the USSR with “’the open door’ policy of China.

Commonly used moth repllent is

Commonly used antiseptic 'Dettol' is a mixture of:

Commonly used laboratory desiccant is:

Commonly used antiseptic 'Dettol' is a mixture of

Commonly used antiseptic 'dettol' is a mixture of ....

Common table sugar is a disachharide of

Common table sugar is more formally described as

Common table salt becomes moist and does not pour easily in rainy seasons because:

Common table salt becomes moist and does not pour easily in rainy season because

Common sugar is

Common salt obtained from sea water contains95% NaCl by mass. The approximate number of molecules present in 10g of the salt is

Common salt obtained from sea-water contains 95% NaCl by mass. The approximate number of molecules present in 10g salt is:

Common salt brings about preservation of pickles by phenomenon of______.

Common reducing reactions of monosaccharides are due to

Common oxidation state of element of atomic number 47 is:

Common name of Propane 2 - ol is ….

Common name of pentanal is -----------.

Common name of HOOC-(CH_(2))_(4)-COOH is

Common name of ethoxybenzene, is anisole

Common name of DDT is

common name of chloroethene is allyl chloride.

Common monomer n melamine formaldehyde and Bakelite

Common monomer in glyptal and terylene is

Common impurities present is Bauxite are :

Common impurities present in bauxite are.....

Commonimpuritiespresentin bauxite are .........

Commericial sample of H_(2)O_(2)is labeled as 10 V. Its % strength is nearly

Commercially nitrogen is prepared from

Commercially methanol is prepared by

Commercially important ore of copper is its

Commercially important ore of lead is :

Commercially available cone. HCI contains 38% HCI by mass density of 1.19 g cm^(3). Calculate the molarity of this solution.

Commercially available concentrated hydrochloric acid contains 38% HCl by mass. (a) What is the molarity of this solution ? The density is 1.19 g cm^(-3) (b) What volume of concentrated hydrochloric acid is required to make 1.00 L of 0.10 M HCl ?

Commercially available concentrated HCIcontains 38.0% HCl by mass (density = 1.19 g mL^(-1)). The molarity of the solution is

CommerciallyavailableconcentratedHC1 isand aqueoussolutioncontaining38%HC1by mass.Ifit densityis 1.1 g cm^(-3) (a) Whatis the molarityof the HC1solutionand ( b)molefractions of HC1 andH_(2)O

Commercially available conc. HCl contains 38% HCl by mass and has a density 1.19 g cm""^(-3). Calculate the molarity of this HCI.

Commercial name 1, 1, 2, 2-tetrachloro-ethane is-.

Commercial detergents contain mainly :

Commercial alcohol is made unfit for drinking by adding

Comment on the statement that the element of the first transition series possess many properties different those of heavier transition elements.

Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.

Comment on the statement that "colloid is not a substance but state of a substance".

Comment on the statement that elements of the first transition series posses many properties different form those of heavier transition elements.

Comment on the statement that "Colloid is not a substance but state of a substance,"

Comment on the statement that "colloid is not a substance but a state of substance".