94420 + Interview Questions in Chemistry in Class 12

1.	The carbonate which decomposes into oxide on heating is :
Answer» `Li_2CO_3` `Na_2CO_3` `K_2CO_3` `CsCO_3` ANSWER :A

Discussion

2.	The carbonate of which of the following cation is insoluble in water?
Answer» `NA^(+)` `K^(+)` `NH_(4)^(+)` `Ca^(2+)` Solution :Alkali metal ION and `NH_(4)^(+)` carbonates are WATER SOLUBLE . All other carbonates are water insoluble .

Discussion

3.	The carbonate of which of the cation is insoluble in water
Answer» `NA^(+)` `K^(+)` `NH_(4)^(+)` `Ca^(2+)` SOLUTION :All other carbonates except those of alkali METALS and AMMONIUM ions are insoluble in water.

Discussion

4.	The carbon-oxygen bond is phenol is slightly stronger than that in methanol. Why?
Answer» Solution :`to` The C-O bond in PHENOL has the PARTIAL double bond CHARACTER DUE to RESONANCE whereas there is no resonance in methanol molecule. So, the C-O bond in phenol stronger than C-O bond in methanol.

Discussion

5.	The carbon-oxygen bond length in phenol is _______.
Answer» 120 PM 136 pm 150 pm 180 pm Answer :B

Discussion

6.	The carbon - oxygen bond in phenol is slightly stronger than that in methanol. Why?
Answer» Solution :This can be explained as under : (i) PHENOL, the conjugation of UNSHARED electron pair over oxygen with aromatic ring results in partial double bond CHARACTER in `C-O` bond. In methanol, no such conjugation (resonance) is possible. (ii) In phenol, oxygen is attached to `sp^(2)` hybridised carbon while in methanol, oxygen is attached to `sp^(3)` hybrised carbon. An `sp^(2)` hybridised carbon is more electronegative (because of greater s - character) than `sp^(3)` hybridised carbon atom. Therefore, the bond between oxygen and `sp^(2)` hybridised carbon is more stable than the bond between oxygen and `sp^(3)` hybridised orbital.

Discussion

7.	The carbon, hydrogen and oxygen in an organic compound have been found to be in the ratio of 3: 4 : 4. If the vapour density of the compound is 104, its molecular formula is :
Answer» `C_(43)H_(4)O_(4)` `C_(3)H_(4)O_(2)` `C_(9)H_(12)O_(12)` `C_(6)H_(8)O_(8)` Solution :The empirical formula , `C_(3)H_(4)O_(4)` Empirical formula mass `=3xx12+4xx1+4xx16=104` Molecular mass `=2xxV.D` `=2xx104=208` `n=(208)/(105)=2` Molecular formula `=(C_(3)H_(4)O_(4))_(2)` `=C_(6)H_(8)O_(8)`

Discussion

8.	The carbon dating is based on
Answer» `._(6)^(15)C` `._(6)^(14)C` `._(6)^(13)C` `._(6)^(11)C` ANSWER :B

Discussion

9.	The carbonyl group is converted into methylene group by :
Answer» <P>CLEMMENSEN REDUCTION Wolff- Kishner reduction RED P + HI All Answer :D

Discussion

10.	The carbon compound "A" forms "B" with sodium metal and again forms "C" with PCI, but "B" reacts with "C" to form diethyl ether. Therefore A, B and C are respectively.
Answer» ` C_2OH,C_2H_5OCl, C_2H_5 O NA` ` C_2 H_5OH , C_2 H_6, C_2 H_5` ` C_2 H_5 CL ,C_2 H_6 , C_2 H_5 Cl` ` C_2 H_5 OH , C_2 , H_ 5 O Na , C_2 H_ 5 Cl` ANSWER :D

Discussion

11.	The carbon chain in fructose is identified by converting in into:
Answer» α-methyl hexane Cyclohexane n-hexane α-methyl caproic acid Answer :C

Discussion

12.	The carbon-carbon double bond the carbon-carbon double bond in a molecule is capable of decolorizing Br_(2)//C Cl_(4) following free radical mechanism. The decolorization of Br_(2)/water solution however shows electrophilic addition. The addition of bromine to cyclopentene provides evidence for bromonium ion immediate in bromine addition. it follows ionic mechanism. when cyclopentene reacts with bromine in presence of C Cl_(4) anti addition occurs and gives trans-isomer so addition of halogen to an alkene is a stereospecific reaction. Cis-alkene on addition with halogen gives meso products and trans alkene on addition gives racemic mixture. Q Trans-2-butene on reacting with Br_(2) in C Cl_(4) forms mainly
Answer» `+-2,3`-DIBROMOBUTANE `+2,3`-dibromobutane `-2,3`-dibromobutane Meso-2,3-dibromobutane Answer :D

Discussion

13.	The carbon-carbon length is saturated, aliphatic compound is:
Answer» `1.33overset@A` `1.54overset@A` `1.39overset@A` `1.45overset@A` ANSWER :B

Discussion

14.	The carbon-carbon bond lengths in naphthalene are not equal. Use a resonance argument to explain why bond (a) is shorter than bond (b).
Answer» SOLUTION :N/A

Discussion

15.	The carbon-carbon bond length is shortest in :
Answer» ethane propane ethene ETHYNE Solution :The carbon-carbon BOND LENGTH is shortest in ethyne because of TRIPLE bond.

Discussion

16.	The carbon-carbon bond length in benzene is :
Answer» same as in `C_(2)H_(4)` in between `C_(2)H_(6) and C_(2)H_(2)` in between `C_(2)H_(4) and C_(2)H_(2)` in between `C_(2)H_(6) and C_(2)H_(4)` Answer :D

Discussion

17.	The carbon-carbon bond cleavage step in a retro-aldol reaction involves, under basic conditions, a leaving group that is an enolate, or under acidic conditions, an enol. Write a mechanism for the retro-aldol reaction of 4-hydroxy-4-methyl 2-pentanone under basic conditions (shown above).
Answer» Solution :Base REMOVES the PROTON from the B-hydroxyl group, setting the STAGE for reversal of the aldol addition. As the alkox ide reverts to the carbonyl group, a carbon-carbon BOND breaks with EXPULSION of the enolate as a leaving group. This liberates one of the original carbonyl molecules. Protonation of the enolate forms the other.

Discussion

18.	The carbon -carbon bond distance in benzene is
Answer» LONGER than a C-C single bond Longer than a C-C DOUBLEBOND Longer than a C=C doublebond Longer than a `C-=C` triple bond ANSWER :B

Discussion

19.	The carbon- basedreductionmethodis NOT usedfortheextractionof
Answer» tin from ` SnO_2 ` IRON from` Fe_2O_ 3 ` ALUMINIUM from alumina magnesiumfrom` MgCO_3.CaCO_3 ` SOLUTION :HighlyelectropositivemetalslikeAlandMg arenot obtainedbyreductionoftheiroxideswith carbonsincetheyformtheircorrespondingcarbides.Insteadtheyareobtainedby electrolyticreductionoftheirfusedsalts,i.e.,AL fromfused`Al_2O_3`andMgfromfused` MgCl _2`

Discussion

20.	The carbon atoms in graphics are
Answer» `SP^(3)`-HYBRIDIZED sp-hybridized `sp^(2)`-hybridized none of these Solution :The carbon atom in graphite are `sp^(2)` -hybridised.

Discussion

21.	The carbon atom of carbonyl group is
Answer» `SP^(3) `- hybridised `sp^(2)` - hybridised sp - hybridised `sp^(3)` - d- hybridised Answer :B

Discussion

22.	The carbon atom in carboxylic group is ...
Answer» `SP^(3)`-hybridized `sp^(2)`-hybridized sp-hybridized unhybridized Solution :(iii) (B) sp²-hybridized

Discussion

23.	The carbohydrates which reduce Tollen's reagent and Fehling's solution are termed as
Answer» non-reducing sugars reducing sugars oxidised sugars both 'B' and 'c' Answer :D

Discussion

24.	The carbohydrates are stored in animal bodies as
Answer» Starch AMYLUM GLYCOGEN Cellulose ANSWER :C

Discussion

25.	The carbohydrates are important constituent of our diet, they function as:
Answer» Bio FUELS of PROVIDE energy Shock absorbing pad Heat INSULATOR None Answer :C

Discussion

26.	which carbohydrate serves as reserve glucose in body ?
Answer» ANSWER :C

Discussion

27.	The carbohydrate used as storage molecule in animal is
Answer» sucrose glycogen maltose glucose Solution :In ANIMALS, the excess glucose is stored in the form of glycogen, which is synthesised and stored MAINLY in LIVER and MUSCLES.

Discussion

28.	The carbohydrate which cannot be hydrolyzed by the human digestive system is :
Answer» Starch Glycogen Cellulose All the above Answer :C

Discussion

29.	The carbinol name of CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)C-OH
Answer» ETHYL PROPYL CARBINOL ethyl methyl carbinol trimethyl carbinol dimethyl isopropyl carbinol ANSWER :C

Discussion

30.	The carbo content of :
Answer» Cast iron is in between that of steel and wrought iron Pig iron is in between that of steel and wrought iron Steel is in between that of cast iron and wrought iron Wrought iron is inbetween that of steel and cast iron ANSWER :C

Discussion

31.	The capacity of an ion to coagulate a colloidal sol depends on
Answer» Its SHAPE MAGNITUDE of its CHARGE The SIGN of charge Both magnitude and sign of the charge Answer :D

Discussion

32.	The Cannizzaro's reaction is not given by :
Answer» Trimethylacetaldehyde Acetaldehyde Benzaldehyde 2-methyl PROPANOL ANSWER :B

Discussion

33.	The Cannizzaro's reaction is not given by
Answer» BENZALDEHYDE CHLORAL METHANAL ETHANAL Solution :Cannizzaro's reaction is GIVES by those aldehydes which have no `alpha` hydrogen atom. Compound (a) has no `alpha` hydrogen atoms, so it shows Cannizzaro's reaction. Compound (b) has no ` alpha` - hydrogen atom but does not show Cannizzaro's reaction, because of- I effect.

Discussion

34.	The cannizzaro reaction of PhCOCHO forms the product(s)
Answer» `PhCOCH_2OH+PhCOCOO^(-)` `PHCH(OH)COO^(-)` `PhCOO^(-)+PhCOCH_2OH` Both A and C Answer :B

Discussion

35.	The cannizaro reaction of PhCOCHO forms the product(s)
Answer» `PhCOCH_(2)OH+PhCOCO_(2)^(-)` `Phunderset(OH)UNDERSET(\|)(C)H-CO_(2)^(-)` `PhCO_(2)^(-)+PhCOCH_(2)OH` Both (A) and (C) ANSWER :B

Discussion

36.	The Cannizzaro reaction is not given by
Answer» trimethylacetaldehyde ACETALDEHYDE benzaldehyde formaldehyde. Solution :acetaldehyde

Discussion

37.	The calorific values of fats, carbohydrates and proteins vary in the order
Answer» `FATS GT CARBOHYDRATES gt `PROTEINS `Fatsgt`proteins `gtcarbohydrates` `Carbohydratesgt`proteins` gtFats` Proteins `gtCarbohydrates gtfats` ANSWER :A

Discussion

38.	The calrofic value is maximum in case of
Answer» MILK PROTEINS MINERAL Carbohydrates Answer :D

Discussion

39.	The calorific values of fats, carbohydrates and proteins vary in the order:
Answer» FATS gt CARBOHYDRATES gt Proteins Fats gt Proteins gt Carbohydrates Carbohydrates gt Proteins gt Fats Proteins gt Carbohydrates gt Fats Answer :B

Discussion

40.	The calorific value of fat is
Answer» Less than that of CARBOHYDRATE and protein Less than that of protein but more than carbohydrate Less than that of carbohydrate but more than that of protein More than that of carbohydrate and protein Solution :FAT has HIGHEST calorific value AMONG the protein, carbohydrate and fat.

Discussion

41.	The 'calorie' used in nutrition is actually a kilocalorie. Assume that a human requires 2500 cal' of energy each day for metabolic activity. What mass of ethanol is needed to provide this energy?C_2H_5OH (l) 3O_2(g) to 2CO_2(g) + 3H_2O(l) , Delta H = -1371kJIf the human body is considered to be a closed system, what would be the temperature increase resulting from this energy intake? Assume a mass of 75 kg and a specific heat of 4 J K^(-1) g^(-1). If the body temperature is to be maintained at a constant value by the evaporation of water, what mass of water must evaporate? Assume that the heat of vaporization of water is 44 kJ "mol"^(-1)
Answer» SOLUTION :`352g, 35K DAY^(-1) , 4292g`

Discussion

42.	The calorific value of carbonmonoxide is about _____k cal:
Answer» `7.8` `11.6` 47 94 Answer :A

Discussion

43.	The calomel electrode is reversible with respect to:
Answer» `Hg_2^(2+)` `H^+` `HG^(2+)` `CI^-` ANSWER :A

Discussion

44.	The calomel electrode is represented by
Answer» `PT , Hg_(2) Cl_(2 (s)) \|KCL _((AQ)) \| Hg` `KCl_((aq))\| Hg_(2) Cl_(2(s)) \|Hg_((l))` `Hg\|KCl_((aq)) \|Hg_(2) Cl_(2(s))` `Hg\|HgCl_((s)) \| KCl_((aq))` Solution :It is REPRESENTATION of calomel electrode .

Discussion

45.	The calomel electrode can be represented as
Answer» `KCl_((aq))\|Hg_(2)Cl_(2(s))\|Hg_((s)), PT` `KCl_((aq))\|Hg_(2)Cl_(2(s))\|H_(2(l)), Pt` `KCl_((aq))\|Hg_(2)Cl_(2(s))\|Hg_((l)), Pt` `Hg_(2)Cl_(2(l))\|KCl_((aq))\|Hg_((l)), Pt` ANSWER :C

Discussion

46.	The calomel electrode is a:
Answer» STANDARD HYDROGEN electrode Reference electrode Platinum electrode Mercury electrode. Answer :B

Discussion

47.	The calomel contain the ion is
Answer» `Hg_(2)^(2+)` `Hg^(+)` `Hg^(2+)` `Hg_(2)^(+)` SOLUTION :`Hg_(2) Cl_(2) (s) HARR Hg_(2)^(2+) + 2 CL^(-)` i.e., `Hg_(2)^(2+)` IONS .

Discussion

48.	The calculated spin magnetic moment of Fe(II) is :
Answer» 4.90 B.M. 4.47 B.M. 5.91 B.M. 0 Solution :Fe(II) HAS4 UNPAIRED elecrtrons. `= sqrt(N (n+2)) = sqrt(4(4 +2))` ` = sqrt(24) = 4.90` B.M.

Discussion

49.	The calculated bond order in superoxide ion is :
Answer» 1.5 1 2.5 2 Solution :The bond ORDER of superoxide ion `O_(2)^(-)`is `O_(2)^(-)to sigma1s^(2)sigma^()1S^(2)sigma2s^(2)sigma^()2S^(2)sigma2p_(Z)^(2)pi2p_(x)^(2)~~pi2p_(y)^(2)pi^()3p_(x)^(2)~~pi^()2p_(y)^(1)` Bond oeder `=1//2[N_(b)-N_(a)]` `=1//2[10-7]=1.5`

Discussion

50.	The calculated magnetic moment of Cu^(2+) ion
Answer» 1.73 B.M zero 2.6 B.M 3.4 B.M Answer :A

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The carbonate which decomposes into oxide on heating is :

The carbonate of which of the following cation is insoluble in water?

The carbonate of which of the cation is insoluble in water

The carbon-oxygen bond is phenol is slightly stronger than that in methanol. Why?

The carbon-oxygen bond length in phenol is _______.

The carbon - oxygen bond in phenol is slightly stronger than that in methanol. Why?

The carbon, hydrogen and oxygen in an organic compound have been found to be in the ratio of 3: 4 : 4. If the vapour density of the compound is 104, its molecular formula is :

The carbon dating is based on

The carbonyl group is converted into methylene group by :

The carbon compound "A" forms "B" with sodium metal and again forms "C" with PCI, but "B" reacts with "C" to form diethyl ether. Therefore A, B and C are respectively.

The carbon chain in fructose is identified by converting in into:

The carbon-carbon length is saturated, aliphatic compound is:

The carbon-carbon bond lengths in naphthalene are not equal. Use a resonance argument to explain why bond (a) is shorter than bond (b).

The carbon-carbon bond length is shortest in :

The carbon-carbon bond length in benzene is :

The carbon-carbon bond cleavage step in a retro-aldol reaction involves, under basic conditions, a leaving group that is an enolate, or under acidic conditions, an enol. Write a mechanism for the retro-aldol reaction of 4-hydroxy-4-methyl 2-pentanone under basic conditions (shown above).

The carbon -carbon bond distance in benzene is

The carbon- basedreductionmethodis NOT usedfortheextractionof

The carbon atoms in graphics are

The carbon atom of carbonyl group is

The carbon atom in carboxylic group is ...

The carbohydrates which reduce Tollen's reagent and Fehling's solution are termed as

The carbohydrates are stored in animal bodies as

The carbohydrates are important constituent of our diet, they function as:

which carbohydrate serves as reserve glucose in body ?

The carbohydrate used as storage molecule in animal is

The carbohydrate which cannot be hydrolyzed by the human digestive system is :

The carbinol name of CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)C-OH

The carbo content of :

The capacity of an ion to coagulate a colloidal sol depends on

The Cannizzaro's reaction is not given by :

The Cannizzaro's reaction is not given by

The cannizzaro reaction of PhCOCHO forms the product(s)

The cannizaro reaction of PhCOCHO forms the product(s)

The Cannizzaro reaction is not given by

The calorific values of fats, carbohydrates and proteins vary in the order

The calrofic value is maximum in case of

The calorific values of fats, carbohydrates and proteins vary in the order:

The calorific value of fat is

The calorific value of carbonmonoxide is about _____k cal:

The calomel electrode is reversible with respect to:

The calomel electrode is represented by

The calomel electrode can be represented as

The calomel electrode is a:

The calomel contain the ion is

The calculated spin magnetic moment of Fe(II) is :

The calculated bond order in superoxide ion is :

The calculated magnetic moment of Cu^(2+) ion