94420 + Interview Questions in Chemistry in Class 12

1.	In collodial state, particle size range from :10−1000Å,20−50Å,1−10Å,1−280Å
Answer» `10 - 1000 Å` `20 - 50 Å` `1 - 10 Å` `1 - 280 Å` ANSWER :A

Discussion

2.	In collision theory according to arrhenius plot, intercept is equal to
Answer» `log_(10)K` In A In K `(-E_(a))/(R)` ANSWER :B

Discussion

3.	In cold countries, ice frozen on roads and footpaths is melted by spraying salts. Explain.
Answer» Solution :Addition of water SOLUBLE salts like `NaCl` or `CaCl_(2)` depresses the FREEZING POINT of water hence ice melts into water. THEREFORE frozen ice can be melted and removed.

Discussion

4.	In cold countries ethylene glycol is added to water in the radiators to:
Answer» BRING down the SPECIFIC HEAT of WATER Lower the viscosity Reduce the viscosity Make water a BETTER lubricant Answer :A

Discussion

5.	In cold countries, ethylene glycol is added to water in the radiators to …………………. .
Answer» BRING down the specific heat of WATER lower the viscosity reduce the viscosity make water a BETTER LUBRICANT Solution :bring down the specific heat of water

Discussion

6.	In cold countries, ethylene glycol is added to water in the radiators of cars during winters. It results in:
Answer» LOWERING in BOILING point Reducing viscosity Reducing SPECIFIC heat Lowering in FREEZING point Answer :D

Discussion

7.	The number of unpaired electron in the complex ion [CoF_(6)]^(3-) is
Answer» 0 4 2 3 Answer :B

Discussion

8.	In coagulation of a (colloidal) solution of As_2S_3, which has maximum coagulating power ?
Answer» NaCl KCl `BaCl_2` `AlCl_3` ANSWER :D

Discussion

9.	In CO_(2), SO_(2), SiO_(2) each central atom is covalently bonded with :-
Answer» 2,2,4 OXYGEN ATOMS respectively 2,2,2 oxygen atoms respectively 2,4,4 oxygen atoms respectively 4,4,4 oxygen atoms respectively Answer :A

Discussion

10.	In Co-ordination compound s. [Cr (en)_3 ][CrF_6]
Answer» a)ligand is EN (ethylenediamine ) b)Oxidation state of central atom is +3 C)Central metal is Cr (in anionic complex ) d)CATION complex is ` [Co(NH_3) _4Cl_2]^(+) ` ANSWER :D

Discussion

11.	In cloud and fog the dispersion medium and dispersed phase is
Answer» GAS - liquid liquid - liquid liquid - gas gas - SOLID Answer :C

Discussion

12.	In Clemmensen reduction, carbonyl compound is treated with________
Answer» ZINC AMALGAM+HCl Sodium amalgam+HCl Zinc amalgam+Nitric acid Sodium amalgam+`HNO_(3)`. ANSWER :A

Discussion

13.	In ClO_(3)^(-) ion, Cl atom undergoes :
Answer» `SP^(2)` HYBRIDISATION `sp^(3)` hybridisation `sp^(3)d` hybridisation `sp^(3)d^(2)` hybridisation. Answer :B

Discussion

14.	In Clemmensen reduction carbonyl compound is treated with ________.
Answer» ZINC amalgam + HCL sodium amalgam + HCl zinc amalgam + nitric acid sodium amalgam + `HNO_(3)` ANSWER :A

Discussion

15.	In Clemensen's reduction, the catalyst used is
Answer» Zn-Hg + conc. HCL `NH_(2)N_(2)+C_(2)H_(5)ONA` `PdCl_(2)//H_(2)O` `(C_(6)H_(5))+C_(2)H_(5)ONa`. Answer :A

Discussion

16.	In Clark's method the chemical used to remove hardness of water us
Answer» `Na_2CO_3` `Ca(OH)_2` NAOH `CaCO_3` ANSWER :B

Discussion

17.	In Claisen condensation , two molecules of ester get condensed in the presence of a strong base to give :
Answer» ACID ANHYDRIDE `BETA` KETO ester Amides Acids. Answer :B

Discussion

18.	In circus method 0.099 g organic compound gave 0.287 g AgCl. The percentage of chlorine in the compound will be
Answer» `28.6` `71.7` `35.4` `64.2` Solution :`%` of CHLORINE `= (35.5)/(143.5) XX (" MASS of" AGCL)/(" Mass of substance") xx 100` ` =(35.5)/(143.5) xx (0.287)/(0.099) xx 100 = 71.71%`

Discussion

19.	In cis- trans isomerism, the compound generally
Answer» contains a triple bond contains a DOUBLE bond possesses an asymmetric carbon atom rotates the plane of polarized light. ANSWER :B

Discussion

20.	Inchromyl chloride test A "______" precipitale fo leadchromateis obtained
Answer» White red YELLOW BLUE ANSWER :C

Discussion

21.	In Chromyl ion oxidation state of chromium is _______
Answer» SOLUTION :`CrO_(2)Cl_(2)(+6)`

Discussion

22.	In chromium chloride(CrCl_(3),Cl^(-)ions have cubic close packed arragement andCr^(3+)ions are present in the octahedral holes. The fraction of the total number of holes occupied is
Answer» `1//3` `1//6` `1//9` `1//12` Solution :In`CrCl _(3)`, for every, 3 `Cl^(-)`ions there is one`CR^(3+)`ions. THUS , if there are `3 Cl^(-)`ions in the packing, octahedral voids = 3, TETRAHEDRAL voids = 6. Total voids = 3 + 6 = 9 . As 1 `Cl^(3+)` ion is present in the void, therfore fractionof HOLES occupied`= 1//9`

Discussion

23.	In chromite ore, the oxidation number of iron and chromium are respectively.
Answer» `+ 3, + 2` `+3, +6` `+2, + 6` `+2, +3` Solution :Chromite ore is `FeCr_(2)O_(4)` Ox. STATE of `FE = + 2 , Cr=+ 3`

Discussion

24.	In chromite ore, the oxidation number of iron and chromium are respectively ........
Answer» `+3, +2` `+3, +6` `+2, +6` `+2, +3` Solution :Chromite ore is `FeCr_(2)O_(4)` Oxidation state of `Fe` is +2 and CR is +3.

Discussion

25.	In chromite are , the oxidation number of iron and chromium respectively ………..
Answer» `+3,+2` `+3,+6` `+2,+6` `+2,+3`. Solution :CHROMITE are is `FeCr_(2)O_(4)`.

Discussion

26.	In chromatography, when the fixed phase is solid, the basis of separation is :
Answer» Adsorption Absorption Solubility Partition Answer :A

Discussion

27.	In chromatographic technique, the relative adsorption of a component in a mixture is expressed in terms of its R_(f) value . It is defined as :
Answer» `("DISTANCE moved by solvent form BASE LINE ")/("Distance moved by the substance from base line")` `("Amount adsorbed by a pure solvent")/("Amount adsorbed by the MIXTURE")` `("Distance moved by the substance from base line ")/("Distance moved by solventfrom base line")` Amount adsorbed per gram of STATIONARY phase. Answer :C

Discussion

28.	In chloroethane, the carbon bearing halogen is bonded to ------ hydrogen(s). It is called --- alkyl halide
Answer» TWO, primary THREE, primary Two, SECONDARY ONE, Tertiary Answer :A

Discussion

29.	In chlorobenzene , the -CI group
Answer» ACTIVATES the benzene RING more VIA resonance effect than deactivating it via inductive effect DEACTIVATES the benzene ring more via inductive effect than ACTIVATING it via resonance effect. activates the benzene ring via resonance effect and deactivates it via inductive effect. Both these effects are evenly matched. is a net deactivating group with meat director characteristics. Answer :B

Discussion

30.	In the chloroethene, the carbon bearing halogen is bonded to…hydrogen(s).It is called__alkylhalide.
Answer» TWO, PRIMARY Three, primary Two, SECONDARY ONE, Tertiary Answer :A

Discussion

31.	In chlorobenzene the Cl group
Answer» activities the benzene ring more via resonane effect then deactivating it iva INDUCTIVE effect deactivates the benzene ring more via inductive effect than deactivating it via resonance effect activates the benzene ring via resonance effect and deactivates it via inductive effect. Both these effectts are evenly match is a net deactivating group with meta directing influence. Solution :CHLORINE activates the benzene ring due to +R effect. The lone pair of electrons on Cl participates in resonance with benzene Because of high electronegativity of Cl, it ALSO exerts -I effect. So thest TWO effects balance each other.

Discussion

32.	In chlorobenzene solutions, the basic strength of amines increases in the order
Answer» ` (C_(2)H_(5))_(3)N lt (C_(2)H_(5))_(2)NH lt C_(2)H_(5)NH_(2)` `C_(2)H_(5)NH_(2)lt (C_(2)H_(5))_(2)NHlt (C_(2)H_(5))_(3)N` `(C_(2)H_(5))_(2)NHltC_(2)H_(5)NH_(2)lt (C_(2)H_(2))_(3)N` `(C_(2)H_(5))Nlt C_(2)H_(5)NH_(2)lt (C_(2)H_(5))_(2)NH` Solution :TN non-aqueous solvents, the basicity of amines does not DEPEND upon the stability o f conjugate ACIDS since H-bonding cannot occur. INSTEAD, it DEPENDS only on the +/-effect of the alkyl groups. Obviously, as the number of alkyl groups increases, the basicity increases. in the same order, i.e., `C_(2)H_(5)NH_(2) lt (C_(2)H_(5))_(2)NHlt (C_(2)H_(5))_(3)N `

Discussion

33.	In chlorine gas, ratio of Cl^(35) and Cl^(37) is
Answer» `1 : 3` `3 : 1` `1 : 1` `1 : 4` Solution :`35.5 = (X XX 37 + (100 -x)35)/(100) rArr 35.5 = (3500 + 2x)/(100)` `2x = 50 rArr x = 25 rArr " Ratio " 75 : 25 = 3 :1`

Discussion

34.	In chlorination the relation rate of abstraction of H in 3^(@), 2^(@) "and" 1^(@)C atom respectively
Answer» 5:3, 8:2 5:3, 8:1 1600:82:1 1600:5:82 Answer :2

Discussion

35.	In chlorination roasting Tin ore is converted into its halide. In this process how many moles of chloride is required
Answer» Solution :Two moles of CHLORIDE REQUIRED in chlorination roasting to convert TIN ORE into its halide `(SnCl_(2))`.

Discussion

36.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. If Avogadro's number is1xx10^(23) mol^(-1) then the mass of one atom of oxygen would be:
Answer» `(16)/(6.02)`AMU `16xx6.02` amu 16 amu `16xx10^(-23)` amu Answer :C

Discussion

37.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. If N_(A) is the Avogadro's number then number of valence electrons in 4.8g of O^(2-) is:
Answer» `2.4N_(A)` `4.2N_(A)` `1.6N_(A)` `3.2N_(A)` ANSWER :A

Discussion

38.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. xL N_(2) gas at STP contains 3xx10^(22) molecules. the number of molecules. in x L ozone at STP will be:
Answer» `3XX10^(22)` `6.02xx10^(23)` `3xx10^(24)` NONE of these. Answer :A

Discussion

39.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. How many atoms are present in 49g of H_(2)SO_(4)?
Answer» `7xx6.023xx10^(23)` `4xx6.023xx10^(23)` `6xx6.023xx10^(23)` `7.xx3.02xx10^(23)` ANSWER :D

Discussion

40.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. The mass of one molecule of water is approximately.
Answer» 1G of butane `(C_(4)H_(10))` 0.5g `1.66xx10^(-24)g` `3.2xx10^(-23)g` Answer :D

Discussion

41.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. The mass of one amu is approximately.
Answer» 1g of BUTANE `(C_(4)H_(10))` 0.5g `1.66xx10^(-24)G` `3.2xx10^(-24)g` ANSWER :C

Discussion

42.	In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14th general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12g of .^(12)C. 1 mole of a gas at STP occupies 22.4 litre volume. molar volume of solids and liquids is not definite Molar mass of a substance is also called gram-atomic mass or gram molar mass. the virtual meaning of mole is plenty. heap of the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. 5.6 litre of a gas at STP are found to have a mass of 22g. the molecvular mass of the gas is:
Answer» 22 44 88 33 Answer :C

Discussion

43.	In chemical terms , what are alums used for purifying water for drinking purposes ?
Answer» Hydrated chlorides DOUBLE nitrate Double sulphates NITRATES of aluminium Solution :Alum is used for all the double sulphates having the composition `M_(2)SO_(4) . M_(2)(SO_(4))_(3) . 24H_(2)O` Where M stands for MONOVALENT basic radicals. ALUMS have Germicide properties and thus used in PURIFICATION of water

Discussion

44.	In chemical scale of relative mass of the isotopic mixture of oxygen atom ( O^16 , O^17 ,O^18) assumed to be equal to:
Answer» 16.002 16 16.2 15..89 Answer :B

Discussion

45.	In chemicalreactionofamines, whichact as
Answer» ELECTROPHILES NUCLEOPHILES NEUTRAL acid Answer :B

Discussion

46.	In chemical reaction of potassium ferrocyanide and hydrogen peroxide in the presence of dil.H_2SO_4
Answer» Ferrocyanide GETS REDUCED to ferricyanide Ferrocyanide gets oxidised Iron does not change its oxidation state Hydrogen peroxide is oxidised ANSWER :B

Discussion

47.	In chemical reaction A hArr B,the system will be know in equilibrium when
Answer» A COMPLETELY changes to B `50%` of A changes to B The rate of change of A to B and B to A on both the SIDE are same Only `10%` of A chages to B Solution :When rate of forward REACTION equal to rate of backward reaction the reaction is said to be in equlibrium.

Discussion

48.	In chemical equilibrium, the value of Delta n (number of molecules), is negative, then the relationship between K_(p) "and" K_(c) will be
Answer» `K_(P)-K_(c) = 0` `K_(c) = K_(P) XX (RT)^(+DELTAN)` `K_(P) = K_(c) xx (RT)^(-Deltan)` `K_(c) = 1/K_(p)` SOLUTION :`Kp = Kc(RT)^(Deltang)` Since, `Delta(NG)` is -ve `Kc = Kp(RT)^(+Deltang)`

Discussion

49.	In chemical equilibrium, the vlue of Deltan (number of molecules of products-number of molecules of reactants) is negative, then the relationship between K_(p)and K_(c) will be
Answer» `K_(p)-K_(c)=0` `K_(p)=K_(c)(RT)^(+DELTAN)` `K_(p)=K_(c)(RT)^(-Deltan)` `K_(p)=(1)/(K_(c))` ANSWER :B

Discussion

50.	In chemical analysis, the presence of a methyl ketonic group is tested with I_(2) in presence of an alkali like NaOH or KOH. In another chemical analysis, aldehyde group is tested either by Tollens' reagent (AgNO_(3)NH_(3)OH) which gives silver mirror or by Fehling's solution (CuSO_(4)+NaOH+ Roschelle salt) which gives red ppt. of copper (I) oxide. Q. Consider the following compounds: I. CH_(3)-overset(O)overset(\|\|)(C)-CH_(2)-overset(O)overset(\|\|)(C)-CH_(3) II. CH_(3)-overset(O)overset(\|\|)(C)-overset(O)overset(\|\|)(C)-CH_(3) III. CH_(3)-overset(O)overset(\|\|)(C)-OH IV. CH_(3)-overset(O)overset(\|\|)(C)-Cl Which will give iodoform test?
Answer» Only I Both I and II Only II All Solution :ALTHOUGH `CH_93)COCH_(2)COCH_(3)` contains a `CH_(3)CO-` group linked to carbon, YET it does not undergo iodoform test. The reason being that the iodination OCCURS at the more reactive `CH_(2)` group rather than at the terminal `CH_(3)` which is essential for iodoform test to occurs. Only `CH_(3)CO-COCH_(3)` gives iodoform test.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In collodial state, particle size range from :10−1000Å,20−50Å,1−10Å,1−280Å

In collision theory according to arrhenius plot, intercept is equal to

In cold countries, ice frozen on roads and footpaths is melted by spraying salts. Explain.

In cold countries ethylene glycol is added to water in the radiators to:

In cold countries, ethylene glycol is added to water in the radiators to …………………. .

In cold countries, ethylene glycol is added to water in the radiators of cars during winters. It results in:

The number of unpaired electron in the complex ion [CoF_(6)]^(3-) is

In coagulation of a (colloidal) solution of As_2S_3, which has maximum coagulating power ?

In CO_(2), SO_(2), SiO_(2) each central atom is covalently bonded with :-

In Co-ordination compound s. [Cr (en)_3 ][CrF_6]

In cloud and fog the dispersion medium and dispersed phase is

In Clemmensen reduction, carbonyl compound is treated with________

In ClO_(3)^(-) ion, Cl atom undergoes :

In Clemmensen reduction carbonyl compound is treated with ________.

In Clemensen's reduction, the catalyst used is

In Clark's method the chemical used to remove hardness of water us

In Claisen condensation , two molecules of ester get condensed in the presence of a strong base to give :

In circus method 0.099 g organic compound gave 0.287 g AgCl. The percentage of chlorine in the compound will be

In cis- trans isomerism, the compound generally

Inchromyl chloride test A "______" precipitale fo leadchromateis obtained

In Chromyl ion oxidation state of chromium is _______

In chromium chloride(CrCl_(3),Cl^(-)ions have cubic close packed arragement andCr^(3+)ions are present in the octahedral holes. The fraction of the total number of holes occupied is

In chromite ore, the oxidation number of iron and chromium are respectively.

In chromite ore, the oxidation number of iron and chromium are respectively ........

In chromite are , the oxidation number of iron and chromium respectively ………..

In chromatography, when the fixed phase is solid, the basis of separation is :

In chromatographic technique, the relative adsorption of a component in a mixture is expressed in terms of its R_(f) value . It is defined as :

In chloroethane, the carbon bearing halogen is bonded to ------ hydrogen(s). It is called --- alkyl halide

In chlorobenzene , the -CI group

In the chloroethene, the carbon bearing halogen is bonded to…hydrogen(s).It is called__alkylhalide.

In chlorobenzene the Cl group

In chlorobenzene solutions, the basic strength of amines increases in the order

In chlorine gas, ratio of Cl^(35) and Cl^(37) is

In chlorination the relation rate of abstraction of H in 3^(@), 2^(@) "and" 1^(@)C atom respectively

In chlorination roasting Tin ore is converted into its halide. In this process how many moles of chloride is required

In chemical terms , what are alums used for purifying water for drinking purposes ?

In chemical scale of relative mass of the isotopic mixture of oxygen atom ( O^16 , O^17 ,O^18) assumed to be equal to:

In chemicalreactionofamines, whichact as

In chemical reaction of potassium ferrocyanide and hydrogen peroxide in the presence of dil.H_2SO_4

In chemical reaction A hArr B,the system will be know in equilibrium when

In chemical equilibrium, the value of Delta n (number of molecules), is negative, then the relationship between K_(p) "and" K_(c) will be

In chemical equilibrium, the vlue of Deltan (number of molecules of products-number of molecules of reactants) is negative, then the relationship between K_(p)and K_(c) will be