94420 + Interview Questions in Chemistry in Class 12

1.	Relation between partial pressure and mole fraction is stated by
Answer» Graham's law RAULT's law Lc-Chatclicr Avogadro law Solution :According to Raoult's law "The partial PRESSURE of a volatile COMPONENT of a solution is DIRECTLY PROPORTIONAL to its mole fraction in solution at any temperatme". `p = P_(x)^(@)` where, p= Partial pressure of componem `p ^(@)=` Vapour pressure of component in pure form x = mole fraction of component in solution.

Discussion

2.	Relation between hydrolysis constant and dissociation constant are given. Which is the correct formula for MgCl_(2).
Answer» `K_(h) = (K_(w))/(K_(a))` `K_(h) = (K_(w))/(K_(b))` `K_(h) = (K_(w))/(K_(a) XX K_(b))` `K_(w) = (K_(h))/(K_(b))` SOLUTION :For a salt of weak base and STRONG acid LIKE `MgCl_(2)`, the relation is as `K_(h) = (K_(w))/(K_(b))`.

Discussion

3.	Relation between magnetic moment (spin-only formula) and number of unpaired electrons is given by
Answer» `mu=sqrt(N(n+2))` `mu=sqrt(n^(2)+1)` `mu=sqrt(n(n+1))` `mu=sqrt(n(n+3))` ANSWER :A

Discussion

4.	Relation between(A) and (B) is
Answer» Anomers Positional isomer Functional isomer Enantiomer Answer :A

Discussion

5.	Relation between degree of dissociation (alpha) and vant Hoff's factor for BaCI_(2) is
Answer» `I = 1 + alpha` `I = 1 + 2 alpha` `i= 1 - alpha` `I = 1 - 2 alpha` Solution :`{:(,BaCI_(2),hArr,BA^(2+),+,2Cl^(-)),("Initial moles",1,,0,,0),("Moles at EQ",1-alpha,,alpha,,2alpha):}` van't-Hoff FACTOR `i=1-alpha +alpha + 2alpha = 1 + 2alpha`

Discussion

6.	Relation between amino acid and protein is similar to the one between
Answer» Glucose and fructose Glucose and strach NUCLEOSIDES and nuleic acid NUCLEOTIDES and NUCLEIC acid Solution :Proteins on COMPLETE hydrolysis GIVES amino acids. Starch on complete hydrolysis gives glucose.

Discussion

7.	Reimer-Tiemann reaction involves an aryl carbanion/enolate anion and also -"CCl"_(3) derived from the action of strong bases on CHCl_(3), though the latter has only a transient existence decomposing to "CCl"_(2), a highly electron deficient electrophile that attacks the aromatic nucleus, the product from phenoxideion is after acidification, very largely the o-aldehyde plus just a small amount of p-isomer. Reimer-Tiemann reaction involves
Answer» nucleophilic substitution electrophilic substitution free RADICAL mechanism IONIC mechanism Answer :B

Discussion

8.	Reimer-Tiemann reaction involves an aryl carbanion/enolate anion and also -"CCl"_(3) derived from the action of strong bases on CHCl_(3), though the latter has only a transient existence decomposing to "CCl"_(2), a highly electron deficient electrophile that attacks the aromatic nucleus, the product from phenoxideion is after acidification, very largely the o-aldehyde plus just a small amount of p-isomer. CO_(2) can attack in a similar mannerto : "CCl"_(2) on phenoxide ion. Following-a similar mechanism, major product will be
Answer» o-hydroxybenzoate p-hydroxybenzoate m-hydroxybenzoate NONE of the above ANSWER :A

Discussion

9.	Reimer Tiemann reaction is an electrophillic substitution reaction in which the electrophile is
Answer» `^+C CI_(3)` `^+CHCI_(2)` `:C CI_(2)` NONE of these Solution :SEE mechanism of Reimer Tiemann reaction.

Discussion

10.	Reimer-Tiemanns reaction involves a
Answer» Carbonium ION INTERMEDIATE Carbene intermediate Carbanion intermediate Free RADICAL intermediate Solution :Reimer-Tiemann reaction involves a carbene intermediate.

Discussion

11.	Reimer-Tiemann reaction involves an aryl carbanion/enolate anion and also -"CCl"_(3) derived from the action of strong bases on CHCl_(3), though the latter has only a transient existence decomposing to "CCl"_(2), a highly electron deficient electrophile that attacks the aromatic nucleus, the product from phenoxideion is after acidification, very largely the o-aldehyde plus just a small amount of p-isomer. The product of the reaction in the reaction in the above paragraph is largely
Answer» m-salicylaldehyde p-salicylaldehyde o-salicylaldehyde NONE of the above ANSWER :C

Discussion

12.	Reimer-Tiemann reaction involves an aryl carbanion/enolate anion and also -"CCl"_(3) derived from the action of strong bases on CHCl_(3), though the latter has only a transient existence decomposing to "CCl"_(2), a highly electron deficient electrophile that attacks the aromatic nucleus, the product from phenoxideion is after acidification, very largely the o-aldehyde plus just a small amount of p-isomer. Name the electrophile attacking carbanion in the above reaction.
Answer» Chloroform Trichloromethyl ANION dichlorocarbene HYDROGEN ion Answer :C

Discussion

13.	Reimer-Tiemann reaction involves an aryl carbanion/enolate anion and also -"CCl"_(3) derived from the action of strong bases on CHCl_(3), though the latter has only a transient existence decomposing to "CCl"_(2), a highly electron deficient electrophile that attacks the aromatic nucleus, the product from phenoxideion is after acidification, very largely the o-aldehyde plus just a small amount of p-isomer. If the above reaction is carried out on the anion of p-hydroxytoluene, what will be theproduct/products?
Answer» Both (A) and (B) NONE of the above ANSWER :C

Discussion

14.	Reimer-Tiemann reaction introduces an aldehyde group, on to the aromatic ring of phenol, ortho to the hydroxyl group. This reaction involves electrophilic aromatic substitution. This is a general method for the synthesis of substituted salicyladehydes as depicted below. The structure of the intermediate I is
Answer» ANSWER :D

Discussion

15.	Reimer-Tiemann reaction introduces an aldehyde group, on to the aromatic ring of phenol, ortho to the hydroxyl group. This reaction involves electrophilic aromatic substitution. This is a general method for the synthesis of substituted salicyladehydes as depicted below. The electrophile in this reaction is
Answer» : CHCL `""^(+)CHCl_(2)` :`"CCL"_(2)` `"CCl"_(3)` ANSWER :D

Discussion

16.	Reimer-Tiemann reaction introduces an aldehyde group, on to the aromatic ring of phenol, ortho to the hydroxyl group. This reaction involves electrophilic aromatic substitution. This is a general method for the synthesis of substituted salicyladehydes as depicted below. Which one of the following reagents is used in the above reaction ?
Answer» `"AQ. NAOH"+CH_(3)Cl` `"aq. NaOH"+CH_(2)Cl_(2)` `"aq. NaOH"+CHCl_(3)` `"aq. NaOH"+"CCL"_(4)` Answer :B

Discussion

17.	Reimer-Tiemann reaction introduces an aldehyde group on to the aromatic ring of phenol, ortho to the hydroxyl group. Thi reaction involves electrophilic aromatic substitution. It is a general method for the synthesis of substituted salicylaldehydes as depicted below: Q. The structure of intermediate (I) is:
Answer» ANSWER :B

Discussion

18.	Reimer-Tiemann reaction introduces an aldehyde group on to the aromatic ring of phenol, ortho to the hydroxyl group. Thi reaction involves electrophilic aromatic substitution. It is a general method for the synthesis of substituted salicylaldehydes as depicted below: Q. Which one of the following reagents is used ini the above reaction?
Answer» AQ. `NaOH+CH_(3)CL` aq. `NaOH+CH_(2)Cl_(2)` aq. `NaOH+CHCl_3` aq. `NaOH+C Cl_(4)` Answer :C

Discussion

19.	Reimer-Tiemann reaction introduces an aldehyde group on to the aromatic ring of phenol, ortho to the hydroxyl group. Thi reaction involves electrophilic aromatic substitution. It is a general method for the synthesis of substituted salicylaldehydes as depicted below: Q. The electrophilic in this reaction is-
Answer» `:CHCL` `.^(o+)CHCl_(2)` `:C Cl_(2)` `**C Cl_(3)` Answer :C

Discussion

20.	Reimer Tieman reaction involves intermediate
Answer» Carbonium ion intermediate CARBENE intermediate CARBANIAN intermediate FREE RADICAL intermediate Solution :NA

Discussion

21.	Regular use of which of the following fertilizer increases the acidity of soil
Answer» POTASSIUM nitrate Urea Superphosphate of lime Ammonium sulphate Solution :`(NH_(4))_(2)SO_(4)` is a salt of strong acid and weak base, on hydrolysis it will PRODUCE `H^(+)` ION. This will increases the acidity of soil. `(NH_(4))_(2) SO_(4) to 2NH_(4)^(+) + SO_(4)^(2-)` `NH_(4)^(+) +H_(2) hArr NH_(4)OH +H^(+)`

Discussion

22.	Reimer and Tiemann reaction is used to prepare
Answer» SALICYLIC acid salicylaldehyde phenyl benzoate picric acid Answer :B

Discussion

23.	Regular use of which of the following fertilizers increases the acidity of soil?
Answer» Urea Superphosphate of lime Ammonium SULPHATE POTASSIUM nitrate. Answer :C

Discussion

24.	Regent 'A' in the followingreaction is H - CHO + CH_(3) - NO_(2) overset(A) to H - overset(OH)overset(\|)underset(H)underset(\|)(C)- CH_(2) - NO_(2)
Answer» 20%KOH 50%KOH alc.KOH `SnCl_(2)+HCL` ANSWER :C

Discussion

25.	Regardint the isolation of noble gases fromatomosphric air by Ramsay - Rayleigh's second method four equations are givenbelow I) N_2 + O_2 + 2NOII) 2NO+ O_2 to 2NO_2 III) 2NO_2+ 2NaOH to NaNO_2+ NaNO_3 + H_2OIV) CaC_2 + N_2 overset(Delta)to CaCN_2+ C In this method, the reactions truely involved are
Answer» Both I and II Both II and III I, II and III III and IV Answer :C

Discussion

26.	Regarding XeF_2the correct combination is
Answer» `sp^3d - 4L.P` `sp^3d-3L.P` `sp^3d - 2L.P` `sp^3d - 1L.P` ANSWER :B

Discussion

27.	Regarding the structure of cyanamide ion, pick out the wrong statement
Answer» It has one carbon with a NEGATIVE charge It has TWO `sigma` bonds It has two `PI` bonds It has two negatively charged NITROGEN atoms Answer :A

Discussion

28.	Regarding XeF_2, the correct combination is (L.P = lone pairs mu = Dipolemoment)
Answer» `sp^3d-4L.P` `sp^3d-3L.P` `sp^3d-2L.P` `sp^3d-1L.P` ANSWER :B

Discussion

29.	Regarding the electrolysis of Alumina, the correct statements A) Cryolite is added to reduce the fusion temp B) Impure aluminium is mixed with copper and silicon to increase the density C) Fluorspar is added to reduce the fusion temp D) Electrolyte is mixture of fluorides of sodium, Barium and Aluminium saturated with Alumina
Answer» Only B, C and D are CORRECT Only A, C and D are correct Only A , B and D are correct Only C is correct Answer :D

Discussion

30.	Regarding the electrolysis of Alunina, the correct statements A) Cryolite is added to increase the fusion temp B) Impure aluminium is mixed with copper and silicon to decrease the density C)Fluorspar is added to reduce the fusion temp D) Electrolyte is mixture of oxides saturated with alumina
Answer» Only B, C and D are CORRECT Only A, C and D are correct Only A,B and D are correct Only C is correct ANSWER :D

Discussion

31.	Regarding tetraamminedithiocyanato-S cobalt tris (oxalato) Cobaltate (III) the correct statements are
Answer» FORMULA of complex in `[Co(SCN)_(2)(NH_(3))_(3)(CN)_(3)]` It is a chelating complex and show linkage ISOMERISM It SHOWS optical isomerism It shows geometrical isomerism Solution :`[(NH_(3))_(4)Co(SCN)_(2)Co("ox")_(3)]`

Discussion

32.	Regarding starch the wrong statement is
Answer» It is PRESENT in SORGHUM It is least soluble in HOT water It is not oxidised by TOLLENS reagent It can FORM osozone Answer :B

Discussion

33.	Regarding SF _(6), the wrong statement is
Answer» It is inert and does not UNDERGO hydrolysis It is a covalent compound Hybridisation of S is `sp^3d^2` and shape is octahedral S forms `SF_6`, in THIRD EXCITED state Answer :D

Discussion

34.	Regarding secondary structure of a protein, correct statement(s) is/are (A) peptide bonds possess regional planarity(B) C = O and -NH- of different peptide chains are held by Van der Waal attarctions (C ) closely packed arrangement so as to minimise repulsion between ''R'' groups.
Answer» only C only B A and B only A and C only ANSWER :D

Discussion

35.	Regarding phenol the correct statements areA) It reacts with B_2//CS_2to give a mixture of o-bromophenol and p-bromophenolB) In Riemer-Tiemann reaction with CHCl_3 a substituted benzalchloride intermediate is formedC) In Kolbe's reaction gives salicylic acidD) On oxidation with it gives a conjugated diketone
Answer» A, B, C only B, C, D only A, B, C, D C, D only Answer :C

Discussion

36.	Regarding ozone the wrong statement is
Answer» The BOND angle is `116^(0)49^(1)` `O_(3)` acts as both oxidant and reductant O-O bond lengths are equal It is paramagnetic Answer :D

Discussion

37.	Regarding oxygen the correct statements are A) It is an important constituent of rocket fuelsB) It is used for artificial respriration C) It is used in oxyacetylene welding.
Answer» A,B A,C B,C A,B,C Answer :D

Discussion

38.	Regarding lactose some statements are given below (A) On hydrolysis lactose gives beta- D-galactose and beta-D-glucose In lactose C_(1) " of " beta - D- galactose has acetal structure and C_(1) " of " beta - D-glucose hashemiacetal structure (C ) In lactose molecule beta- D-galactose is a nonreducing unit and beta-D- glucose is a reducing unit The correct statements are
Answer» A, C A, B B, C A, B, C Answer :D

Discussion

39.	Regarding molarity, which of the following statements are correct (a) Units of molarity mol kg^(-1) (b) Molarity of dibasic acid is half of its normality (c) Normality x GEW / GMW (d) Molarity always equals to its molality
Answer» a,b a,b b,C a,c Answer :C

Discussion

40.	Regarding H_(3)PO_(5) the wrong statement is
Answer» It's basicity is three Oxidation state P in it +5 It contains O - O LINKAGE It can FORM a DIMER Answer :4

Discussion

41.	Regarding enzymatic reactions, the 4 steps are shown below A) E + S rarr E -S B) E-P rarr E + P (C) E - I rarr E - P D) E - S rarr E-I The correct sequence of the steps is
Answer» A,D,C,B A,B,C,D D,C,B,A A,C,B,D Answer :A

Discussion

42.	Regarding enzymes, incorrect statement is
Answer» an enzyme is GENERALLY a protein an enzyme may be a CONJUGATED protein enzyme GETS deactivated during reactions enzyme gets activated during reactions ANSWER :D

Discussion

43.	Regarding diethyl ether, the wrong statement is
Answer» It is slightly soluble in water In cold condition, it does not REACT with ALKALI and dilute acids It has ACTIVE hydrogen It does not react with Na metal Answer :C

Discussion

44.	Regarding cross-linked or network polymers, which of the following statements is incorrect ?
Answer» They contain strong covalent bonds in their polymer chains. They contain covalent bonds between various linear polymer chains. EXAMPLES are BAKELITE and melamine. They are formed from bi- and tri-functional monomers. Solution :They contain strong covalent bonds in their polymer chains. In this TYPE of polymers, bifunctional or trifunctional monomer combines with covalent BOND INBETWEEN the long polymer chain. Long polymer chain is joined by strong covalent bond and forms a net like structure.

Discussion

45.	Regarding cross-linked or network polymers, which of the following statement is incorrect?
Answer» EXAMPLES are Bakelite and melamine They are formed from bi and tri-functional monomers They contain COVALENT BONDS between VARIOUS linear polymer chains They contain strong covalent bonds in their polymer chain Solution :They contain strong covalent bonds in their polymer chain

Discussion

46.	Regarding amylopectin, the wrong statement is
Answer» it is a branched CHAIN polysaccharide it is insoluble in water it GIVES blue colour with iodine solution ONE molecule may contain 25-30 D-glucose units Answer :C

Discussion

47.	Refractory metals are used in construction of furnaces because
Answer» they can withstand HIGH temperature they are CHEMICALLY inert their melting POINT is high their BOILING point is LOW Answer :A

Discussion

48.	Refractory materials are used for the construction of furnaces because they :
Answer» are light in weight can STAND with HIGH TEMPERATURE are leak proof do not REQUIRE to be REPLACED Answer :B

Discussion

49.	Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property ?
Answer» Solution :As the SOLID has the same value of refractive index along all DIRECTIONS, it is isotropic. It is therefore amorphous solid. Amorphous SOLIDS when CUT with a knife or on breaking do not show a clean cleavage.

Discussion

50.	Reformatsky reaction involves a carbonyl compound and
Answer» `CH_(2)=CHCO OH` `C H_(2)(CO OC_(2)H_(5))_(2)` `RCBr_(2)CO OC_(2)H_(5)` `RCHBrCO OC_(2)H_(5)` ANSWER :D

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Relation between partial pressure and mole fraction is stated by

Relation between hydrolysis constant and dissociation constant are given. Which is the correct formula for MgCl_(2).

Relation between magnetic moment (spin-only formula) and number of unpaired electrons is given by

Relation between(A) and (B) is

Relation between degree of dissociation (alpha) and vant Hoff's factor for BaCI_(2) is

Relation between amino acid and protein is similar to the one between

Reimer Tiemann reaction is an electrophillic substitution reaction in which the electrophile is

Reimer-Tiemanns reaction involves a

Reimer Tieman reaction involves intermediate

Regular use of which of the following fertilizer increases the acidity of soil

Reimer and Tiemann reaction is used to prepare

Regular use of which of the following fertilizers increases the acidity of soil?

Regent 'A' in the followingreaction is H - CHO + CH_(3) - NO_(2) overset(A) to H - overset(OH)overset(|)underset(H)underset(|)(C)- CH_(2) - NO_(2)

Regardint the isolation of noble gases fromatomosphric air by Ramsay - Rayleigh's second method four equations are givenbelow I) N_2 + O_2 + 2NOII) 2NO+ O_2 to 2NO_2 III) 2NO_2+ 2NaOH to NaNO_2+ NaNO_3 + H_2OIV) CaC_2 + N_2 overset(Delta)to CaCN_2+ C In this method, the reactions truely involved are

Regarding XeF_2the correct combination is

Regarding the structure of cyanamide ion, pick out the wrong statement

Regarding XeF_2, the correct combination is (L.P = lone pairs mu = Dipolemoment)

Regarding the electrolysis of Alunina, the correct statements A) Cryolite is added to increase the fusion temp B) Impure aluminium is mixed with copper and silicon to decrease the density C)Fluorspar is added to reduce the fusion temp D) Electrolyte is mixture of oxides saturated with alumina

Regarding tetraamminedithiocyanato-S cobalt tris (oxalato) Cobaltate (III) the correct statements are

Regarding starch the wrong statement is

Regarding SF _(6), the wrong statement is

Regarding secondary structure of a protein, correct statement(s) is/are (A) peptide bonds possess regional planarity(B) C = O and -NH- of different peptide chains are held by Van der Waal attarctions (C ) closely packed arrangement so as to minimise repulsion between ''R'' groups.

Regarding ozone the wrong statement is

Regarding oxygen the correct statements are A) It is an important constituent of rocket fuelsB) It is used for artificial respriration C) It is used in oxyacetylene welding.

Regarding molarity, which of the following statements are correct (a) Units of molarity mol kg^(-1) (b) Molarity of dibasic acid is half of its normality (c) Normality x GEW / GMW (d) Molarity always equals to its molality

Regarding H_(3)PO_(5) the wrong statement is

Regarding enzymatic reactions, the 4 steps are shown below A) E + S rarr E -S B) E-P rarr E + P (C) E - I rarr E - P D) E - S rarr E-I The correct sequence of the steps is

Regarding enzymes, incorrect statement is

Regarding diethyl ether, the wrong statement is

Regarding cross-linked or network polymers, which of the following statements is incorrect ?

Regarding cross-linked or network polymers, which of the following statement is incorrect?

Regarding amylopectin, the wrong statement is

Refractory metals are used in construction of furnaces because

Refractory materials are used for the construction of furnaces because they :

Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property ?

Reformatsky reaction involves a carbonyl compound and