52671 + Interview Questions in Chemistry in Class 11

1.	Benzene favours ……………. Substitution reaction.
Answer» ANSWER :ELECTROPHILIC

Discussion

2.	Benzene, ethane and ethylene belong to the family of hydrocarbons. Show how the data given below is in consistent with the law of Multiple Proportions. {:("Compound",underset("in 5.0 g of the sample")("Mass of carbon"),underset("in 5.0 g of the sample")("Mass of hydrogen")),("Benzene","4.61 g","0.39 g"),("Ethane","4.00 g","1.00 g"),("Ethylene","4.29 g","0.71 g"):} .
Answer» Solution :Let 1 g of hydrogen be the fixed MASS of hydrogen In benzene : 1.00 g of hydrogen are combined with carbon = 4.61 g 1.00 g of hydrogen are combined with carbon `= ((4.61g))/((0.39g))xx(1.0g)=11.82g` In ethane : 1.00 g of hydrogen are combined with carbon = 4.00 g In ethylene : 0.71 g of hydrogen are combined carbon = 4.29 g 1.00 g of hydrogen are combined with carbon `= ((4.29g))/((0.71g))xx(1g)=6.04g` Ratio by mass of carbon combined with 1 g of hydrogen in the three samples `11 : 82 : : 4.00 : 6.04 ::6 : 2 : 3` Since it is a simple whole number ratio, the LAW of MULTIPLE Proportions is obeyed.

Discussion

3.	Benzene easily shows
Answer» RING fission reactions SINCE it is unstable addition reactions since it is unsaturated electrophilic SUBSTITUTION reactions DUE to stable ring and high `pi` electron density nucleophilic substitution reactions due to stable ring and minimum electron density. Answer :C

Discussion

4.	Benzene does not undergo addition reaction easily because
Answer» It has six hydrogen atoms It has a cyclic structure Double bonds present in benzene are STRONG Resonance STABILISED system is to be preserved. ANSWER :D

Discussion

5.	Benzene does not readily undergo
Answer» halogenation nitration sulphonation oxidation Answer :D

Discussion

6.	Benzene burns in oxygen according to the equation 2C_(6)H_(6(l))+15O_(2(g))rarr12CO_(2(g))+6H_(2)O_((l)). How many litres of oxygen are required at STP for the complete combustion of 39g of liquid benzene?
Answer» `11.2` `22.4` 42 84 Solution :`39g=(1)/(2)` MOLE IMPLIES moles of `O_(2)=(15)/(4)` implies VOLUME = `(15)/(4)xx22.4=84`

Discussion

7.	Benzene burns with sooty flame in burner, because….
Answer» it is ALIPHATIC compound it is aromatic it is cyclic compound due to RESONANCE effect Solution :In aromatic compound, carbon amount is HIGH so on incomplete combustion gives SOOTY flame.

Discussion

8.	Benzene burns with a luminous flame.
Answer» ANSWER :T

Discussion

9.	Benzene burns according to the following equation: 2C_(6)H_(6)(l)+15O_(2)(g)to12CO_(2)(g)+6H_(2)O(l) DeltaH^(@)=-6542 KJ//mol what is the DeltaE^(@) for the combustion of 1.5 mol of benzene?
Answer» `-3271 KJ` `-9813KJ` `-4906 KJ` NONE of these Answer :d

Discussion

10.	Benzene and nitrobenzene can be separated by using ………………..
Answer» SIMPLE DISTILLATION Chromatography Crystallisation STEAM distillation SOLUTION :Steam distillation

Discussion

11.	Benzene and aniline are liquids. Their mixture can be sepearated by
Answer» dil - NaOH dil - HCl distillation diethyl ETHER SOLUTION :ANILINE, being basic, reacts with HCl and hence can be separeated by USING dil. HCl.

Discussion

12.	Benzamide is subjected to Hoffmann's bromamide reaction, the product formed is
Answer» Benzene Benzanilade Benzalamine ANILINE Solution :`UNDERSET("Benzamide")(C_(6)H_(5)CONH_(2)) + 4KOH + Br_(2) RARR underset("Aniline")(C_(6)H_(5)NH_(2)) + K_(2)CO_(3) + 2KBr + 2H_(2)O`

Discussion

13.	Benzaldoxime can exist in two geometrical isomeric forms known as
Answer» CIS and trans dextro and levo syn and anti E and Z Solution :

Discussion

14.	Benzaldehyde and propionaldehyde are the ozonolysis products of
Answer» 2-phenylbut-2-ene 2-phenylbut-1-ene 1-phenylbut-1-ene 1-phenylbut-2-ene ANSWER :C

Discussion

15.	Bent, sp
Answer» Trigonal, `sp^(2)` Octahedral, `sp^(3) d^(2)` Tetrahedral, `sp^(3)` ANSWER :D

Discussion

16.	Bent molecule having dipole moment among the following
Answer» `F_2 O` `H_2 O` `Cl_2 O` ALLOF these Answer :D

Discussion

17.	Liquid benzene burns in oxygen according to 2C_(6)H_(6)(1)+150_(2)(8) to12CO_(2),(g)+6H_(2)O(g). How many litres of oxygen are required for complete combustion of 39g of liquid C_(6)H_(6) (atomic wt.of C=12, 016)?
Answer» 11.2 22.4 42 84 Answer :D

Discussion

18.	Benezene reacts with CI_(2)in the presenece of sunlight to give ………………
Answer» SOLUTION :BHC(BENZENE hexachloride)

Discussion

19.	Benezene reacts with bromine in the presence of AICI_(3)to form bromobenzene and it is an example of ……………….reaction
Answer» SOLUTION :ELECTROPHILICSUBSTITUTION

Discussion

20.	Bell metal is an alloy of copper and
Answer» Tin Aluminium Zinc Nickel Answer :A

Discussion

21.	Bell metal contains 80% copper . The mass of Bell metal which contain 1.5 xx 10^(20) atoms of copper is (Cu = 64)
Answer» 2 mg 20 mg 40 mg 12.8 mg ANSWER :B

Discussion

22.	[Be(H_(2)O)_(4)]CI_(2) on heating gives
Answer» `O_(2)` Be `BeCI_(2)` `[Be(OH)_(4)]^(2-)` ANSWER :D

Discussion

23.	BeH_(2)is preparedreducingBeCl_(2) with________.
Answer» `HCI` `LiAIH_(4)` `H_(2)` `NaBH_(4)` Answer :B

Discussion

24.	BeH_(2) contains three centre two electron bond.
Answer» ANSWER :T

Discussion

25.	BeH_2 and MgH_2 are ionic and _________ in nature.
Answer» ANSWER :POLYMERIC

Discussion

26.	BeH_(2) & MgH_(2) are propared using the reagent
Answer» LIH `AlH_(3)` `LiAlH_(4)` All Answer :3

Discussion

27.	BeH_(2) & MgfH_(2) are prepared using the reagent
Answer» LIH `AlH_(3)` `LiAlH_(4)` All Answer :3

Discussion

28.	Be_((g))toBe^(+) _(g),Delta H=-xKJ//mol. In the reaction of Be(g)to Be^(=2) (g),DeltaH is approximately in KJ/mol
Answer» 2x 3x 4x 8x Answer :2

Discussion

29.	BeF_(2) is highly soluble in water, whereas the fluorides of other alkaline earth metals are almost insoluble because
Answer» `BeF_(2)` is ionic in nature `BeF_(2)` is covalent in nature Hydration energy of `BeF_(2)` is much HIGHER than LATTICE energy Lattice energy of `BeF_(2)` is much higher than its hydration energy Answer :C

Discussion

30.	BeF_2has zero dipole moment where as H_2 Ohas a dipole moment because
Answer» ` H_2 O` is a linear molecule `H_2 O` is a bent molecule F is more electronegative than O Hydrogen BONDING is PRESENT in `H_2 O` ANSWER :B

Discussion

31.	BeF_(2)ispreparedin thepresenceof CO_(2)bythermal decompositionof ___
Answer» `(NH_(4))BeF_(2)` `(NH_(4))_(2) Be F_(4) ` ` (NH_(4))_(2)BEF` `BeF_(3)` ANSWER :B

Discussion

32.	Bees wax is
Answer» Myricy palmiate Myricyl stearate Mixture of HIGHER HYDROCARBONS Myricyloleate Solution :BEES WAX is myricyl PALMITATE

Discussion

33.	BeCl_(2)overset(‘x’)rarrBeH_(2), Here 'X' is
Answer» `NAOH` `H_(2)` `LiAlH_(4)` All Answer :C

Discussion

34.	Beckmann rearrangement of followed by hydrolysis will yield
Answer» BENZOIC ACID and benzlylamine Phenylacetic acid and aniline Benzoic acid and aniline Phenyl ACETIC acid and BENZYL amine Solution :

Discussion

35.	BeCI_(2)+N_(2)O_(4)rarrAunderset("Vacuumn")overset(50^(@)C)rarrBoverset(125^(@)C)rarrC. The compounds A. B and C are
Answer» `BEO.Be(NO_(2))_(2).Be(NO_(3))_(2)` `BeO,Be(NO_(3))_(2),Be(NO_(2))_(2)` `Be(NO_(3))_(2),2N_(2)O_(4),Be(NO_(3))_(2),(Be(NO_(2))_(2)` `Be(NO_(3))_(2).2N_(2)O_(4).Be(NO_(3))_(2)[Be_(4)O(NO_(3))_(6)]` Answer :D

Discussion

36.	BeCI_(2)+LiAIH_(4)rarrX-LiCI +AICI_(3)
Answer» X is LiH X is `BeH_(2)` X is `BeCI_(2)2H_(2)O` None Solution :`2BeCi_(2) + LiAIH_(4) rarr 2BeH_(2) + LICI + AICI_(3)`

Discussion

37.	Because of which bond three dimensional structure is formed in ice ?
Answer» COVALENT BOND HYDROGEN bond Ionic- bond Metallic bond Answer :B

Discussion

38.	BeC_(2)O_(4) and BaC_(2)O_(4) are heated separately with Bunsen burner. The solid residue obtained are respectively:
Answer» `BeO` and `BaO` `BeO` and `BeCO_(3)` `BeCO_(3)` and `BaCO_(3)` `BeCO_(3)` and `BaCO_(3)` Answer :B

Discussion

39.	BeC+4H_(2)O to Be(OH)_(2)+CH_(4) CaC_(2)+2H_(2)O to Ca(OH)_(2)+X Mg_(2)C_(3)+2H_(2)O to Mg (OH)_(2)+Y The total no. of pi bonds present in X and Y
Answer» SOLUTION :`Be_(2)C+4H_(2)O to Be(OH)_(2)+CH_(4)`, `CaC_(2)+2H_(2)OtoCa(OH)_(2)+H-Cunderset(X)(-=)C-H` `Mg_(2)C_(3)+2H_(2)O to mg(OH)_(2)+CH_(2)underset(X)(-)C-=C-H` `ul{:(x"has" 2pi"bonds"),(Y "has" 2pi "bonds"),("TOTAL" 4PI "bonds"):}`

Discussion

40.	Be_(2)C+H_(2)O to Be(OH)_(2)+[X]X is
Answer» `C_(2)H_(2)` `CH_(3)-C-=C-H` `C_(2)H_(6)` `CH_(4)` Solution :`Be_(2)C+4H_(2)Oto2Be(OH)_(2)+CH_(4)uarr`

Discussion

41.	Be_(2)C+4H_(2)O to 2X+CH_(4) X+2OH^(-)toY (X) and (Y) formed in the above two reactions is
Answer» `BeCO_(3)` and `Be(OH)_(2)` respectively `Be(OH)_(2) and BeCl_(2)` respectively `Be(OH)_(2) and [Be(OH)_(4)}^(2-)` respectively `[Be(OH)_(4)]^(2-) and BeCl_(2)` respectively Answer :C

Discussion

42.	Be^(2+) is isoelectronic with which of the following ions ?
Answer» `H^(+)` `LI^(+)` `Na^(+)` `Mg^(2+)` Solution :Both `Be^(2+)` and `Li^(+)` have two ELECTRONS `(1 s^(2))` and hence are isoelectronic .

Discussion

43.	Be^(2+) is isoelectronic with
Answer» `Mg^(2+)` `NA^+` `Li^+` `H^+` ANSWER :C

Discussion

44.	Be reacts with excess of caustic soda to form
Answer» `Be(OH)_(2)` `BeO` `Na_(2)[Be(OH)_(4)]` `Be(OH)_(2).BeCO_(3)` Solution :`Be(OH)_(2)+2NAOH to Na_(2)[Be(OH)_(4)]` `Be(OH)_(2)*BeCO_(3)`

Discussion

45.	Be' has, as compared to "Mg"
Answer» Less electronegativity More IONISATION potential larger atomic radius Lower MELTING point Solution :Be. has more IP VALUE than MG

Discussion

46.	"Be" differs from rest of the elements of the IIA group due to
Answer» SMALL SIZE low electro negativity presence of VACANT 'd' orbital Absence of vancent 'd' ORBITALS Solution :Be. has smaller size and vacant .d. orbitals

Discussion

47.	Beryllium differs from other alkaline earth metals because of
Answer» Small SIZE and high EN Large size and LOW EN Small size low EN Largesize and high EN Solution :The abnormal behaviour of Be is due to its small size and high EN when COMPARED withj other ELEMENTS in the II group.

Discussion

48.	Be and Mg from amongst the p-block elements and most of the d-block elements give metallic or interstitial hydrides on reacting with hydrogen. The density of each compound is less than that of the metal itself and the properties are not much different from that of the metal. They give out hydrogen easily and are strong reducing agents. This suggests that hydrogen is present in the atomic state. these compounds are non-stoichiometric. the f-block elements (i.e., lanthanide and actinides) also form non-stoichiometric hydrides. These hydrides have lower densities than their respective metals. The metals of group 7,8 and 9 do not form hydrides. This region of the periodic table is called 'hydride gap'. Interstitial hydride can not be used as,
Answer» storing `H_(2)` CATALYSTS for HYDROGENATION reaction ROCKET PROPELLANT Electric conductor Solution :Interstitialhydride can not be used as Rocket propellent.

Discussion

49.	Be and Mg from amongst the p-block elements and most of the d-block elements give metallic or interstitial hydrides on reacting with hydrogen. The density of each compound is less than that of the metal itself and the properties are not much different from that of the metal. They give out hydrogen easily and are strong reducing agents. This suggests that hydrogen is present in the atomic state. these compounds are non-stoichiometric. the f-block elements (i.e., lanthanide and actinides) also form non-stoichiometric hydrides. These hydrides have lower densities than their respective metals. The metals of group 7,8 and 9 do not form hydrides. This region of the periodic table is called 'hydride gap'. Which of the following has highest electrical conductance?
Answer» `BeH_(2)` `MgH_(2)` `CaH_(2)` `ZrH_(2)` SOLUTION :N//A

Discussion

50.	Be and Mg from amongst the p-block elements and most of the d-block elements give metallic or interstitial hydrides on reacting with hydrogen. The density of each compound is less than that of the metal itself and the properties are not much different from that of the metal. They give out hydrogen easily and are strong reducing agents. This suggests that hydrogen is present in the atomic state. these compounds are non-stoichiometric. the f-block elements (i.e., lanthanide and actinides) also form non-stoichiometric hydrides. These hydrides have lower densities than their respective metals. The metals of group 7,8 and 9 do not form hydrides. This region of the periodic table is called 'hydride gap'. Which type of hydride is formed by the element having atomic number, Z=43?
Answer» METALLIC HYDRIDE SALINE hydride COVALENT hydride No hydride Solution :TC does not from hydride.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Benzene favours ……………. Substitution reaction.

Benzene easily shows

Benzene does not undergo addition reaction easily because

Benzene does not readily undergo

Benzene burns in oxygen according to the equation 2C_(6)H_(6(l))+15O_(2(g))rarr12CO_(2(g))+6H_(2)O_((l)). How many litres of oxygen are required at STP for the complete combustion of 39g of liquid benzene?

Benzene burns with sooty flame in burner, because….

Benzene burns with a luminous flame.

Benzene burns according to the following equation: 2C_(6)H_(6)(l)+15O_(2)(g)to12CO_(2)(g)+6H_(2)O(l) DeltaH^(@)=-6542 KJ//mol what is the DeltaE^(@) for the combustion of 1.5 mol of benzene?

Benzene and nitrobenzene can be separated by using ………………..

Benzene and aniline are liquids. Their mixture can be sepearated by

Benzamide is subjected to Hoffmann's bromamide reaction, the product formed is

Benzaldoxime can exist in two geometrical isomeric forms known as

Benzaldehyde and propionaldehyde are the ozonolysis products of

Bent, sp

Bent molecule having dipole moment among the following

Liquid benzene burns in oxygen according to 2C_(6)H_(6)(1)+150_(2)(8) to12CO_(2),(g)+6H_(2)O(g). How many litres of oxygen are required for complete combustion of 39g of liquid C_(6)H_(6) (atomic wt.of C=12, 016)?

Benezene reacts with CI_(2)in the presenece of sunlight to give ………………

Benezene reacts with bromine in the presence of AICI_(3)to form bromobenzene and it is an example of ……………….reaction

Bell metal is an alloy of copper and

Bell metal contains 80% copper . The mass of Bell metal which contain 1.5 xx 10^(20) atoms of copper is (Cu = 64)

[Be(H_(2)O)_(4)]CI_(2) on heating gives

BeH_(2)is preparedreducingBeCl_(2) with________.

BeH_(2) contains three centre two electron bond.

BeH_2 and MgH_2 are ionic and _________ in nature.

BeH_(2) & MgH_(2) are propared using the reagent

BeH_(2) & MgfH_(2) are prepared using the reagent

Be_((g))toBe^(+) _(g),Delta H=-xKJ//mol. In the reaction of Be(g)to Be^(=2) (g),DeltaH is approximately in KJ/mol

BeF_(2) is highly soluble in water, whereas the fluorides of other alkaline earth metals are almost insoluble because

BeF_2has zero dipole moment where as H_2 Ohas a dipole moment because

BeF_(2)ispreparedin thepresenceof CO_(2)bythermal decompositionof ___

Bees wax is

BeCl_(2)overset(‘x’)rarrBeH_(2), Here 'X' is

Beckmann rearrangement of followed by hydrolysis will yield

BeCI_(2)+N_(2)O_(4)rarrAunderset("Vacuumn")overset(50^(@)C)rarrBoverset(125^(@)C)rarrC. The compounds A. B and C are

BeCI_(2)+LiAIH_(4)rarrX-LiCI +AICI_(3)

Because of which bond three dimensional structure is formed in ice ?

BeC_(2)O_(4) and BaC_(2)O_(4) are heated separately with Bunsen burner. The solid residue obtained are respectively:

BeC+4H_(2)O to Be(OH)_(2)+CH_(4) CaC_(2)+2H_(2)O to Ca(OH)_(2)+X Mg_(2)C_(3)+2H_(2)O to Mg (OH)_(2)+Y The total no. of pi bonds present in X and Y

Be_(2)C+H_(2)O to Be(OH)_(2)+[X]X is

Be_(2)C+4H_(2)O to 2X+CH_(4) X+2OH^(-)toY (X) and (Y) formed in the above two reactions is

Be^(2+) is isoelectronic with which of the following ions ?

Be^(2+) is isoelectronic with

Be reacts with excess of caustic soda to form

Be' has, as compared to "Mg"

"Be" differs from rest of the elements of the IIA group due to

Beryllium differs from other alkaline earth metals because of