94420 + Interview Questions in Chemistry in Class 12

1.	A sugar contains 4 carbon atoms and the functional group lg -CHO group. Identify the type of sugar and give an example for it.
Answer» Solution :The type of SUGAR that contains 4 carbon atoms and -CHO group is ALDOTETROSE. EXAMPLE of Aldotetrose is ERYTHROSE.

Discussion

2.	A sudden large jump between the values of second and third ionisation enthalpies of an element would be associated with the electronic configuration:
Answer» `1s^2, 2s^2 2p^6, 3s^1` `1s^2, 2s^2 2p^6, 3s^2 3P1` `1s^2, 2s^2 2p^6, 3s^2 3p^2` `1s^2, 2s^2 2p^6, 3s^2` ANSWER :D

Discussion

3.	A sudden large difference between the values of second and third ionization energies to elements would be associated with which of the following electronic configuration
Answer» `1s^(2)2s^(2)2p^(6)2s^(1)` `1s^(2)2s^(2)2p^(6)3s^(2)` `1s^(2)2s^(2)2p^(6)3s^(2)3p^(1)` `1s^(2)2s^(2)2p^(6)3s^(2)3p^(2)` Solution :It is evident that release of 2 electron from the isolated gaseous element shown in option (b) WOULD give RISE to highly stable cor EOF Ne. Hence, massive energy is required to remove the `3^(rd)` electron.

Discussion

4.	A sudden jump between second and third ionisation enthalpies of an atom would be asssociated with the electronic configuration
Answer» `1s^(2)2s^(2)2p^(6)` `1s^(2)2s^(2)2p^(6)3S^(2)3p^(1)` `1s^(2)2s^(2)2p^(6)3s^(2)3p^(2)` `1s^(2)2s^(2)2p^(6)3s^(2)` ANSWER :C

Discussion

5.	(A) Sucrose is not a reducing sugar. (R) In sucrose, glucose is in pyranose form and fructose is in furanose form.
Answer» Both A & R are TRUE and R is the CORRECT explanation of A Both A & R are true, but R is not the correct explanation of A A is true, R is false A is false, R is true ANSWER :B

Discussion

6.	(A) Sucrose is an example of reducing sugar. (R) Sucrose gives silver mirror test with Tollens reagent.
Answer» Both A & R are true and R is the CORRECT explanation of A Both A & R are true, but R is not the correct explanation of A A is true, R is false A is false, R is true ANSWER :B

Discussion

7.	A substances associate in their solution as dimer ( opr bimolecule ) , then what will be the value of Van't Hoff factor i?
Answer» `0.2` `0.4` `0.5` Given all SOLUTION :`i = ("M ( Theoretical )")/("M (Observed)") = (1)/(2)`

Discussion

8.	(A) Substances whose solutions cannot pass through filter paper are called as colloids. (R ) The size of collidal particles are larger than the size of suspension particles.
Answer» Both (A) and (R) are TRUE and (R) is the CORRECT explanation of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is FALSE (A) is false but (R) is true Answer :C

Discussion

9.	A substance X when heated with sulphuric acid liberates a gas which turns starch paper blue. The substance is
Answer» `NaNO_(3)` `NaBr` `Nal` `NaCl` ANSWER :C

Discussion

10.	A substance X when heated with sulphuric acid liberates a gas which turns starch paper blue.
Answer» NaCl NaBr NaI `NaNO_3` ANSWER :C

Discussion

11.	A substance X when heated with conc. H_2SO_4 , liberates a gas which turns starch paper blue. The substance X is
Answer» `NAL` `NABR` `NACL` `NaNO_3` ANSWER :1

Discussion

12.	A substance with initial concentration of 'a' mol dm^(-3) reacts according to zero order kinetics . The time it takes for the completion of the reaction is (k = rate constant )
Answer» k/a a/2k a/k 2k/a ANSWER :C

Discussion

13.	A substance with initial concentration a follows zero order kinetics with rate constant k mol L^(-1)s^(-1). Inhow much time will the reaction go to completion?
Answer» SOLUTION :`K=(a)/(t) or t=(a)/(k)`. In TIME `(a)/(k)` the REACTION will be COMPLETED.

Discussion

14.	A substance with initial concentration 'a' follows zero order kinetics. In how much time will the reaction go to completion ?
Answer» SOLUTION :`(DX)/(dt)=K" or "dx=k" dt ":.x=kt+1.` When `t=0,x=0. :.I=0.` Hence, `x=kt" or "t=x//k`. For COMPLETION, `x=a:.t=a//k`

Discussion

15.	A substance with half life period 4 days is taken to another place in 12 days. The amount of substance left now is
Answer» `1/4` `1/8` `1/16` `1/32` ANSWER :B

Discussion

16.	A substance will be deliquescent if its vapour pressure is:
Answer» EQUAL to the ATMOSPHERIC pressure Equal to that of water VAPOURIN the AIR GREATER than that of water vapour in the air Lesser than that of water vapour in the air Answer :D

Discussion

17.	A substance which turns blue when treated with water is:
Answer» `CuSO_4` `CuSO_4. 5H_2O` `CoSO_4` `Au_2(SO_4)_3` ANSWER :A

Discussion

18.	A substance which reacts with gangue to from fusble material is called
Answer» FLUX Catalyst Ore Slag Solution :`UNDERSET("INFUSIBLE")("Gangue") ("Impurity")+"flux" rarr underset("FUSIBLE")("Slag")`

Discussion

19.	A substance which reacts with gangue to form easily fusible material is called
Answer» FLUX slag ore catalyst Solution :Flux

Discussion

20.	A substance which is used for the purpose of diagnosis, prevention, cure or relief of a disease is called_____.
Answer» hormone vitamin drug nucleic acid Answer :C

Discussion

21.	A substance which is not paramagnetic is :
Answer» `CR(ClO_4)_3` `KMnO_4` `TiCl_3` `VOBr_2` ANSWER :B

Discussion

22.	A substance which gives a yellowprecipitate when boiled with an excess of nitric acidand ammonium molybdate and red precipitate with AgNO_3 is
Answer» ORTHOPHOSPHATE pyrophosphate metaphosphate hypophosphate SOLUTION :`{:("Orthosphosphate" + "Amm.molybdate" underset(DELTA)overset(HNO_(3))to"yellow ppt."),(underset("Red ppt.")darr+AgNO_(3)):}`

Discussion

23.	A substance which gives a brick red flame and breaks down on heating giving oxygen and brown gas is:
Answer» Calcium carbonate Magnesium carbonate Magnesium nitrate Calcium nitrate Solution :`2Ca(NO_(3))_(2)overset(Delta)rarr2CaO+underset(BROWN gas)(4NO_(2))+O_(2)`

Discussion

24.	A substance which gives a brick red flame and breaks down on heating givingoxygen and a brown gas is,
Answer» CALCIUM CARBONATE MAGNESIUM nitrate Magnesium carbonate Calcium nitrate Answer :D

Discussion

25.	A substance which forms micelles in solutions contains
Answer» CARBOXYLIC GROUP Alkyl group WATER insoluble long hydrocabon groups and water soluble polar groups Water soluble hydrocarbon group and water insoluble polar group] Answer :C

Discussion

26.	A substance which destroys the activity of a catalyst is
Answer» NEGATIVE CATALYST CATALYTIC POISON both (a) and (B) promoter Answer :B

Discussion

27.	A substance which completely destroys or reduces the activity of the catalyst is called:
Answer» Catalyst Inhibitor Promotor Catalyst poison Answer :B

Discussion

28.	A substance which can act both as antiseptic and disinfectant is
Answer» Aspirin Chloroxylenol Bithional Phenol Solution :Phenol has ANTISEPTIC as well as disinfectant(KILL Bacteria) QUALITY.

Discussion

29.	The compound which acts both as antipyretic as well as analgesic is
Answer» ASPIRIN Chloromycetin Seconal Bithional. Answer :A

Discussion

30.	A substance which can act both as an antiseptic and disinfectant is
Answer» ASPIRIN phenol analgin sodium pentothal. Solution :`0.2%` solution of phenol acts as an antiseptic and its `1%` solution is a DISINFECTANT.

Discussion

31.	A substance which can act both as antiseptic and disinfectant is :
Answer» Aspirin Chlroxylenol Bithional Phenol Answer :D

Discussion

32.	A substance which can act both as an analgesic and antipyretic is
Answer» quinine ASPIRIN penicillin insulin. Solution :Aspirin can ACT both as an ANTIPYRETIC as WELL as ANALGESIC.

Discussion

33.	A substance undergoes a series of chemical reaction as shown Aoverset(k_(1))toBoverset(k_(2))toCoverset(k_(3))toD with rate constant k_(1)=(In2)/(2000) sec^(-1),k_(2)=(In2)/(10)sec^(-1),k_(3)=20 In 2 sec^(-1) What will be the value of ([A])/([C]) once steady stateis obtained? {[] represents concentration}
Answer» 40000 20000 200 400 Answer :A

Discussion

34.	A substance undergoes sequential decay to give B, Cand D as shown: Aoverset(10^(-3)sec^(-1))toBoverset(10^(6)sec^(-1))toCoverset(10^(12)sec^(-1))toD Calculate the ratio of moles of 'A' to moles of 'C' assuming steady State is obtained.
Answer» 0 `10^(9)` `10^(15)` `10^(3)` Answer :C

Discussion

35.	A substance which alters the rate of a reaction is known as :
Answer» Promoter Catalyst Activator Initiator Answer :B

Discussion

36.	A substance used as a moderator in nuclear reactors is
Answer» Cadminum Uranium-235 Lead HEAVY water Solution :Heavy water `(D_(2)O)` is used as a MODERATOR in nuclear REACTOR

Discussion

37.	A substance undergoes first order decomposition. It follows two first order reaction as follow:
Answer» `75%` B and `25%` C `80%` B and `20%` C `90%` B and `10%` C `76.83%` B and `23.17%` C. Solution :The percentage distribution of B and C are in the RATIOS of their rate constants. `% of B= k_(1)/(k_(1) XX k_(2)) xx 100` `=76.83%` `% of C=100 - 76.83 = 23.17%`

Discussion

38.	A substance undergoes a first order decomposition. The decomposition follows two parallel first order reactions as The percentage distribution of B and C are
Answer» `80%` B and `20%` C `75%` B and `25%` C `90%` B and `10%` C `60%` B and `40%` C Answer :B

Discussion

39.	A substance that will reduce Ag^+ to Ag but will not reduce Ni^(2+) to Ni is :
Answer» Zn Pb Mg Al Answer :B

Discussion

40.	A substance reacts according to the according to the first roder rate law and the specific reaction rate for the reaction is 1xx10^(-2) s^(-1). If the initial concentration is 1.0 M. (a) What is the initial rate ? (b) What is the reaction rate after 1 minutes ?
Answer» Solution :(a) Initial rate of a first ORDER reaction =KC `=1xx10^(-2)xx1.0` `=1xx10^(-2)" MOL L"^(-1)s^(-1)` (B) Concentration after 60 second is calculated by applying the first order kinetic equation , `k(2.303)/60log_101/(1-x)` or `1xx10^(-2)=(2.030)/60[-log(1-x)]` or `(60xx10^(-2))/(2.303)=-log(1-x)=0.2605` `log(1-x)=-0.2605=1.73395` `(1-x) = antilog of (1.7395)` `=0.5489" mol L"^(-1)`

Discussion

41.	A substance produced by the micro organism which can inhibit the growth of other micro organismis called
Answer» Antiseptic ANTIBIOTIC ANTIMICROBIAL Disinfectant Solution :a substance produced by microbe to KILL disease CAUSING microorganism CALLED antibiotic

Discussion

42.	A substance on treatment with dil H_(2)SO_4 liberates a colourless gas which produces (i) turbidity with baryta water and (ii) turns acidified dichromate solution green. The reaction indicates the presence of
Answer» `CO_(3)^(2-)` `S^(2-)` `Mg^(2+)` `NO_(2)^(-)` SOLUTION :`Na_(2)SO_(3)+2HCl(dil.)to2NaCl+H_(2)O+SO_(2),K_(2)Cr_(2)O_(7)+H_(2)SO_(4)+3SO_(4)^(2-)toK_(2)SO_(4)+underset((green))(Cr_(2)(SO_(4))_(3))+H_(2)O`

Discussion

43.	A substance on treatment with dil H_(2)SO_(4) liberates a colourless gas which produces (i) turbidity with baryts water and (ii) terms acidicfied dichromate solution green .The reaction inducates the presencve of
Answer» `CO_(3)^(2-)` `S^(2-)` `SO_(3)^(2-)` `NO_(2)^(Θ)` Solution :`BaSO_(3) + 2HCI(DIL) rarr 2NaCI + H_(2)O + SO_(2)` `K_(2)Cr_(2)O_(7) + H_(2)SO_(4) + 3SO_(2) rarr K_(2)SO_(4) + H_(2)O + Cr_(2)(SO_(4))_(3) GREEN `

Discussion

44.	A substance on hydrolysis in the presence of acid gives a mixture of glucose and fructose. Name the substance.
Answer» SOLUTION :SUCROSE

Discussion

45.	A substance is found to have a magnetic moment of 3.9B.M. Howmany unparied electrons does it contain ?
Answer» SOLUTION :USING the formula, `mu = SQRT(n ( n+2)) B.M.,n = 3`

Discussion

46.	A substance is hygroscopic at a constant temperature if vapour pressure of its saturated solution is
Answer» more than the VAPOUR PRESSURE of WATER in theatmosphere equal to the vapour pressure of water in the atmosphere less than the vapour pressure of water in the atmosphere None of these Solution :A LEVEL INFORMATION

Discussion

47.	A substance is efflorescent at a particular level if its vapour pressure is
Answer» more than that of WATER VAPOUR in the atmosphere equal to that of water vapour in the atmosphere less than that of water vapour in the atmosphere None of these Solution :A LEVEL INFORMATION

Discussion

48.	A substance is completely trimerised on dissolution in a solvent. The van.t Hoff factor (i) for such change is:
Answer» 1 2 3 1/3 Answer :D

Discussion

49.	A substance has a very large fuel value. I g of its complete combustion will give more of :
Answer» `CO_2` WATER vapour Ash gas Calories Answer :D

Discussion

50.	A substance gives ninhydrin test. It is most likely a:
Answer» Lipid Vitamin Carbohydrate Protein ANSWER :A

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A sugar contains 4 carbon atoms and the functional group lg -CHO group. Identify the type of sugar and give an example for it.

A sudden large jump between the values of second and third ionisation enthalpies of an element would be associated with the electronic configuration:

A sudden large difference between the values of second and third ionization energies to elements would be associated with which of the following electronic configuration

A sudden jump between second and third ionisation enthalpies of an atom would be asssociated with the electronic configuration

(A) Sucrose is not a reducing sugar. (R) In sucrose, glucose is in pyranose form and fructose is in furanose form.

(A) Sucrose is an example of reducing sugar. (R) Sucrose gives silver mirror test with Tollens reagent.

A substances associate in their solution as dimer ( opr bimolecule ) , then what will be the value of Van't Hoff factor i?

(A) Substances whose solutions cannot pass through filter paper are called as colloids. (R ) The size of collidal particles are larger than the size of suspension particles.

A substance X when heated with sulphuric acid liberates a gas which turns starch paper blue. The substance is

A substance X when heated with sulphuric acid liberates a gas which turns starch paper blue.

A substance X when heated with conc. H_2SO_4 , liberates a gas which turns starch paper blue. The substance X is

A substance with initial concentration of 'a' mol dm^(-3) reacts according to zero order kinetics . The time it takes for the completion of the reaction is (k = rate constant )

A substance with initial concentration a follows zero order kinetics with rate constant k mol L^(-1)s^(-1). Inhow much time will the reaction go to completion?

A substance with initial concentration 'a' follows zero order kinetics. In how much time will the reaction go to completion ?

A substance with half life period 4 days is taken to another place in 12 days. The amount of substance left now is

A substance will be deliquescent if its vapour pressure is:

A substance which turns blue when treated with water is:

A substance which reacts with gangue to from fusble material is called

A substance which reacts with gangue to form easily fusible material is called

A substance which is used for the purpose of diagnosis, prevention, cure or relief of a disease is called_____.

A substance which is not paramagnetic is :

A substance which gives a yellowprecipitate when boiled with an excess of nitric acidand ammonium molybdate and red precipitate with AgNO_3 is

A substance which gives a brick red flame and breaks down on heating giving oxygen and brown gas is:

A substance which gives a brick red flame and breaks down on heating givingoxygen and a brown gas is,

A substance which forms micelles in solutions contains

A substance which destroys the activity of a catalyst is

A substance which completely destroys or reduces the activity of the catalyst is called:

A substance which can act both as antiseptic and disinfectant is

The compound which acts both as antipyretic as well as analgesic is

A substance which can act both as an antiseptic and disinfectant is

A substance which can act both as antiseptic and disinfectant is :

A substance which can act both as an analgesic and antipyretic is

A substance undergoes sequential decay to give B, Cand D as shown: Aoverset(10^(-3)sec^(-1))toBoverset(10^(6)sec^(-1))toCoverset(10^(12)sec^(-1))toD Calculate the ratio of moles of 'A' to moles of 'C' assuming steady State is obtained.

A substance which alters the rate of a reaction is known as :

A substance used as a moderator in nuclear reactors is

A substance undergoes first order decomposition. It follows two first order reaction as follow:

A substance undergoes a first order decomposition. The decomposition follows two parallel first order reactions as The percentage distribution of B and C are

A substance that will reduce Ag^+ to Ag but will not reduce Ni^(2+) to Ni is :

A substance reacts according to the according to the first roder rate law and the specific reaction rate for the reaction is 1xx10^(-2) s^(-1). If the initial concentration is 1.0 M. (a) What is the initial rate ? (b) What is the reaction rate after 1 minutes ?

A substance produced by the micro organism which can inhibit the growth of other micro organismis called

A substance on treatment with dil H_(2)SO_4 liberates a colourless gas which produces (i) turbidity with baryta water and (ii) turns acidified dichromate solution green. The reaction indicates the presence of

A substance on treatment with dil H_(2)SO_(4) liberates a colourless gas which produces (i) turbidity with baryts water and (ii) terms acidicfied dichromate solution green .The reaction inducates the presencve of

A substance on hydrolysis in the presence of acid gives a mixture of glucose and fructose. Name the substance.

A substance is found to have a magnetic moment of 3.9B.M. Howmany unparied electrons does it contain ?

A substance is hygroscopic at a constant temperature if vapour pressure of its saturated solution is

A substance is efflorescent at a particular level if its vapour pressure is

A substance is completely trimerised on dissolution in a solvent. The van.t Hoff factor (i) for such change is:

A substance has a very large fuel value. I g of its complete combustion will give more of :

A substance gives ninhydrin test. It is most likely a: