Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

In Hofmann bromamide reation, the carbonyl group is lost as______

Answer»

SOLUTION :CARBONATE ION `(CO_(3)^(2-))`
2.

In Goldschmidt aluminothermic process, thermite contains

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3 PARTS of `Al_(2)O_(3) and 4 `parts of AL
3 parts of `Fe_(2)O_(3) and 2` parts of Al
3 parts of `Fe_(2)O_(3)` and 1 part of Al
1 part of `Fe_(2)O_(3)` and 1 part of Al

Solution :3 parts of `Fe_(2)O_(3)` and 1 part of Al.
3.

In Hofmann's hypobromidereaction

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Thealkylgroupin amide MIGRATE to oxygenatom
The ALKYLGROUP in amidemigrateto oxygenatom
There is a no migrationof alkylgroupofamide
Hydrogenatom is migratedto carbonyloxgyen atom of amide

ANSWER :A
4.

In Hofmann bromamide degradation reaction R-overset(O)overset("||")C-NH_(2)+KOH+Br_(2)rarr intermediates are:

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`RCONHBr`
`RNCO`
`RNH_(2)`
none of these

Answer :A::B
5.

In Hoffmann Bromamide reaction which substance is treated with Br_(2)" and "NaOH to obtain amine ?

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Isonitrile
Nitrile
AMIDE
Nitro

Answer :C
6.

In Hoffinann bromamide reaction, the reactive intermediate involved is a

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CARBOCATION
Carbanion
CARBENE
Nitrine.

Solution :See A-Level INFORMATION.
7.

In HO-overset(O)overset(||)S-OH the oxidation states of S are

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`+4,-2`
`+4,0`
`+2,-2`
`+4,-4`

ANSWER :A
8.

In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism.Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them.A space-fitting model of this structure, called hexagonal closed-packed (HCP), is constitution of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible Three spheres are then placed over the first layer so that they touch each other and represent the second layer.Each one of these three spheres touches three spheres of the bottom layer.Finally, the second layer is covered with third layer that is identical to the bottom layer in relative position.Assume radius of even sphere to be 'r'. In hcp lattice, if a plane is drawn parallel to layers A and B at a distance c/8 above the layer B, it passes through centres of x tetrahedral and y octahedral voids.A plane parallel to layer A at a distance c/8 just below it passes through centres of p tetrahedral and q octahedral voids.Find (x+y+p+q) c is the cell parameter of hcp lattice, the vertical edge length.

Answer»

10
9
6
14

Solution :x=7, y=0,p=3,q=0
9.

In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism.Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them.A space-fitting model of this structure, called hexagonal closed-packed (HCP), is constitution of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible Three spheres are then placed over the first layer so that they touch each other and represent the second layer.Each one of these three spheres touches three spheres of the bottom layer.Finally, the second layer is covered with third layer that is identical to the bottom layer in relative position.Assume radius of even sphere to be 'r'. The volume of this HCP unit cell is :

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`12sqrt2 r^3`
`24sqrt2 r^3`
`16sqrt2 r^3`
`64/(3sqrt3)r^3`

Solution :`C=sqrt2/3` 4r=HEIGHT of the UNIT CELL
BASE area`=6xxsqrt3/4(2r)^2`
Volume of the hexagon=Area of base x Height `=6.sqrt2/3 a^2xxc=24sqrt2.r`
10.

In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (hcp), is constitued of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer so that they touch each other and represent the second layer. Each one of these three spheres touched three spheres of the bottom layer. Finally, the second layer is convered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'. The volume of this hcp unit cell is

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`24 SQRT(2)r^(3)`
`16 sqrt(2)r^(3)`
`12 sqrt(2)r^(3)`
`(64r^(3))/(3sqrt(3))`

Answer :A
11.

In hexagonalprimitiveunit cell, the Corneris sharedby:

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4 UNIT cells
6 unit cells
3 unit cells
8 unit cells

ANSWER :B
12.

In hexacyanomanganate (II) ion the Mn atom assumes Id^2sp^3 hybrid state. The number of unpaired electrons in the complex is:

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1
2
3
zero

Answer :A
13.

In hexacyanomanganate (II) ion the Mn atom assumes d^2sp^3 hybrid state. The number of unpaired electrons in the complex is

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1
2
3
zero

Answer :A
14.

In hexacyanomanganate (II) ion the Mn atom assumes a^2sp^3-hybrid states. The number of unpaired electrons in the complex is

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1
2
3
0

Answer :A
15.

In heterogeneous catalytic reactions involving solid catalyst and gaseous reactants, the catalysts, most generally used are

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METALS 
METAL OXIDES only 
TRANSITION metals only 
transition metals and transition metal oxides 

ANSWER :D
16.

In heterogeneous catalytic reactions, catalyst in the finely divided form possesses higher catalytic reactivity. This is because

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SURFACE area of the finely DIVIDED CATALYST is large 
surface area of the catalyst in the LUMP form is large 
finely divided catalyst has more internal energy in it 
finely divided catalyst has stable surface

Answer :A
17.

In He^(o+) ion sample e^(-) is in ground state. If photon of energy 52.24 eV is given to the sample all the atom goes to higher energy state. It again falls back up to ground state. If it is not emitting any lines in Balmer series then what is the maximum possible number of spectral lines observed

Answer»


ANSWER :6
18.

In HCP or CCP constituent particles occupy 74% of the available space. The remaining space (26%) in between the spheres remains unoccupied and is called interstitial voids or holes.Considering the close packing arrangement, each sphere in the second layer rests on the hollow space of the first layer, touching each other. The void created is called tetrahedral void. If R is the radius of the spheres in the close packed arrangement then,R (radius of tetrahedral void) = 0.225 R In a close packing arrangement, the interstitial void formed by the combination of two triangular voids of the first and second layer is called octahedral coid. Thus, double triangular void is surrounded by six spheres. The centre of these spheres on joining, forms octahedron. If R is the radius of the sphere. in a close packed arrangement then,R (radius of octahedral void = 0.414 R).If the anions (A) form hexagonal close packing and cations (C ) occupy only 2/3rd octahedral voids in it, then the general formula of the compound is

Answer»

AB
`A_(3)B_(2)`
`A_(2)B`
`AB_(3)`

ANSWER :B
19.

In HCP or CCP constituent particles occupy 74% of the available space. The remaining space (26%) in between the spheres remains unoccupied and is called interstitial voids or holes.Considering the close packing arrangement, each sphere in the second layer rests on the hollow space of the first layer, touching each other. The void created is called tetrahedral void. If R is the radius of the spheres in the close packed arrangement then,R (radius of tetrahedral void) = 0.225 R In a close packing arrangement, the interstitial void formed by the combination of two triangular voids of the first and second layer is called octahedral coid. Thus, double triangular void is surrounded by six spheres. The centre of these spheres on joining, forms octahedron. If R is the radius of the sphere. in a close packed arrangement then,R (radius of octahedral void = 0.414 R).In Schottky defect

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cations are missing from the lattice sites and OCCUPY the interstitial sites
EQUAL number of cations and ANIONS are missing
anions are missing and electrons are present in their place
equal number of EXTRA cations and electrons are present in the interstitial sites

Answer :B
20.

In HCP or CCP constituent particles occupy 74% of the available space. The remaining space (26%) in between the spheres remains unoccupied and is called interstitial voids or holes.Considering the close packing arrangement, each sphere in the second layer rests on the hollow space of the first layer, touching each other. The void created is called tetrahedral void. If R is the radius of the spheres in the close packed arrangement then,R (radius of tetrahedral void) = 0.225 R In a close packing arrangement, the interstitial void formed by the combination of two triangular voids of the first and second layer is called octahedral coid. Thus, double triangular void is surrounded by six spheres. The centre of these spheres on joining, forms octahedron. If R is the radius of the sphere. in a close packed arrangement then,R (radius of octahedral void = 0.414 R).Mark the false statement :

Answer»

CsCl CRYSTAL shows Schottky DEFECT
Crystals having F - centres are COLOURED and paramagnetic
Photosensitivity of AGBR is due to the presence of Frenkel defect in this crystal.
None of the above

ANSWER :D
21.

In HCP or CCP constituent particles occupy 74% of the available space. The remaining space (26%) in between the spheres remains unoccupied and is called interstitial voids or holes.Considering the close packing arrangement, each sphere in the second layer rests on the hollow space of the first layer, touching each other. The void created is called tetrahedral void. If R is the radius of the spheres in the close packed arrangement then,R (radius of tetrahedral void) = 0.225 R In a close packing arrangement, the interstitial void formed by the combination of two triangular voids of the first and second layer is called octahedral coid. Thus, double triangular void is surrounded by six spheres. The centre of these spheres on joining, forms octahedron. If R is the radius of the sphere. in a close packed arrangement then,R (radius of octahedral void = 0.414 R).In the spinel structure, oxide ions are cubic close packed whereas 1/8th of tetrahedral voids are occupied by A^(2+) cations and 1/2 of octahedral voids are occupied by B^(3+) cations. The general formula of the compound having spinel structure is

Answer»

`A_(2)B_(2)O_(4)`
`AB_(2)O_(4)`
`A_(2)B_(4)O_(2)`
`A_(4)B_(2)O_(2)`

ANSWER :B
22.

In HCP or CCP constituent particles occupy 74% of the available space. The remaining space (26%) in between the spheres remains unoccupied and is called interstitial voids or holes.Considering the close packing arrangement, each sphere in the second layer rests on the hollow space of the first layer, touching each other. The void created is called tetrahedral void. If R is the radius of the spheres in the close packed arrangement then,R (radius of tetrahedral void) = 0.225 R In a close packing arrangement, the interstitial void formed by the combination of two triangular voids of the first and second layer is called octahedral coid. Thus, double triangular void is surrounded by six spheres. The centre of these spheres on joining, forms octahedron. If R is the radius of the sphere. in a close packed arrangement then,R (radius of octahedral void = 0.414 R).In the figure given below, the site marked as S is a

Answer»

tetrahedral VOID
CUBIC void
OCTAHEDRAL void
None of the above

ANSWER :C
23.

In HCI molecule, expected value of dipole momentis 6.12 D but experimental value is 1.03 D. Then, the percentage ionic character will be

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`16.13`
`15.14`
`6.02`
`18.9`

ANSWER :A
24.

In hcp arrangement the coordination number is

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6
12
8
10

Answer :B
25.

In the HCOO^- the two carbon-oxygen bonds are found to be of equal length. What is the reason for it?

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The anion is obtained by the removal of a PROTON from the acid MOLECULE
Electronic orbitals of carbon atoms are hybridised
The C=O bond is weaker than C-O bond
The anion `"HCOO"^(-)` has two resonating STRUCTURES

SOLUTION :In `"HCOO"^(-)`, the two carbon oxygen bond are of equal LENGTH because the anion `"HCOO"^(-)` has two resonating structure.
26.

In HCHO carbon atom has hybridisation:

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SP
`sp^2`
`sp^2`
None

Answer :B
27.

In halogentionof nitroalkane

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all halogonare replacedby HALOGENES
all `ALPHA` -H are REPLACED byhalogens
all `beta` - H are replaced byhalogens
ONLYONE `alpha` -Hreplacedby halogaen

Answer :B
28.

In halogens, which of the following decreases from fluorine to iodine?

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BOND length
Electronegativity
The IONIZATION ENERGY of the element
Oxidizing power

Answer :B::C::D
29.

In halogens, which of the following increases from iodine to fluorine?

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BOND LENGTH
electronegativity
the ionization energy of the element
oxidising power

Solution :In group 17, electronegativity, IE and oxidising power DECREASES from top to bottom. HENCE, all these properties increases from iodine to FLUORINE.
30.

In halogen family which element forms strongest hydrogen bonds ?

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SOLUTION :FLUORINE
31.

In haloarenes C-Cl bond has partial double bond character, which is due to

Answer»

INDUCTIVE effect
electromertic
RESONANCE
STERIC effect

Answer :C
32.

In Hall's process, the ore is mixed with :

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Coke
Sodium carbonate
Sodium hydroxide
Calcium carbonate

Answer :B
33.

In Hall's process, the main reagent mixed with…

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`NAF`
`Na_3AlF_6`
`AlF_3`
`AlF_6`

ANSWER :B
34.

In Hall-Herold process, act as an anode.

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CARBON blocks
hydrogen
copper rods
Zinc rods

Answer :A
35.

In Hall and Heroult's process, products liberated at anode and cathode are _________.

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OXYGEN and aliminium respectively
carbon MONOXIDE and aluminium respectively
carbon DIOXIDE and aliminium respectively
All of these

Answer :D
36.

In hall and Heroult's process , the molten electrolyte is covered with the layer of powdered coke, which help to _________

Answer»

PREVENT oxidation
prevent redcution
prevent loss of heat due to ratiation
both (A) and (C)

ANSWER :D
37.

In halides, halogen atom is attached to

Answer»

`SP^(3)` hybridised carbon atom
`sp^(2)` hybridised carbon atom
sp hybridised carbon atom
sp-d hybridised carbon atom

Answer :B
38.

In haemoglobin the metal ion present is .

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`FE^(2+)`
`ZN^(2+)`
`CO^(2+)`
`CU^(2+)`

Answer :A
39.

In haemoglobin the iron shows oxidation state:

Answer»

`+2`
`+3`
`+1`
`+4`

ANSWER :A
40.

In Haber's process of manufacture of ammonia, the Fe catalyst is poisoned by the pressure of .............

Answer»

Mo
Co
`H_2S`
`As_2O_3`

SOLUTION :`H_2S`
41.

In haemoglobin the iron shows oxidation state :

Answer»

`+2`
`+3`
`+1`
`+4`

Answer :B
42.

In Haber's process, hydrogen is obtained by reacting methane with steam in presence of Nio as catalyst. The process is known as steam reforming. Why is it necessary to remove CO when ammonia is obtained by Haber's process ?

Answer»

Solution :CO acts as a poison for the catalyst in the manufacture of AMMONIA by Haber.s PROCESS. Hence, it is NECESSARY to remove it.
43.

In Haber's process, hydrogen is obtained by reacting methane with steam in presence of Nio as catalyst. The process is known as steam reforming. Why is it necessary to remove CO when ammonia is obtained by Haber's process?

Answer»

Solution :It is necessary to REMOVE CO while obtaining ammonia from Heber PROCESS because, produced CO gas EFFECTS on the reactivity of iron CATALYST.
44.

In Haber's process for manufacture of ammonia which metals acts as a promotor for iron ?

Answer»

Cu
Zn
Mo
As

Answer :C
45.

In Haber's process for NH_3 the temperature and pressure are respectively

Answer»

`STP`
`200-250^0C`, 450 ATM
`450^0C` and 200-250 atm
`100^0C` and 25-50 atm

Answer :C
46.

In haber process 30 litres of dihydrogen and 30 littres of dinitorgen were taken for reaction which yieided only 50% of the expected product. What will be the composition of gaseous mixture under these condition in the end

Answer»

20 litres ammonia, 25 litres NITROGEN, 15 litres hydrogen
20 litres ammonia, 20 litres nitrogen, 20 litres hydrogen
10 litres ammonia, 25 litres notrogen, 15 litres hydrogen
20n litres ammonia, 10 litres notrogen, 30 litres hydrogen

Solution :`N_(2)+2H_(2)hArr2NH_(3)`
`{:(30,30,0),(30-x,30-3x,2x):}`
`{:(,N_(2)=30-5=25 litre),(,H_(2)=30-3xx5=15litre),(,NH_(3)=2xx5=10 litre):}`
47.

In Haber process, 30 litres of dihydrogen and 30 litres of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be the composition of the gaseous mixture under the aforesaid condition in the end?

Answer»

20 litres `NH_3`, 25 litres `N_2`, 20 litres `H_2`
10 litres `NH_3`, 25 litres `N_2`, 15 litres `H_2`
20 litres `NH_3`, 10 litres `N_2`, 30 litres `H_2`
20 litres `NH_3`, 25 litres `N_2`, 15 litres `H_2`

Solution :`N_(2)(g) + 3H_(2)(g) 1 L of `N_(2)` REACTS with 3 L of `H_(2)` to form 2 L of `NH_(3)`.
Thus, `N_(2)` is the limiting reacant.
10 L `N_(2)` will react with 30 L `H_(2)` to form 20 L `NH_(3)`. As actual yield is 50% of the EXPECTED value, `NH_(3)` formed = 10 L, `N_(2)` reacted = 5L, `H_(2)` reacted = 15 L
`THEREFORE` Mixture will contain 10 L `NH_(3), 25 L N_(2), 15 L H_(2)`
48.

In Haber process, 30 litres of dihydrogen and 30 litres of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be the compositon of the gaseous mixture under the aforesaid condition in the end?

Answer»

20 litres `NH_(3)`, 25 litres `N_(2)`, 20 litres `H_(2)`
10 litres `NH_(3)`, 25 litres `N_(2)`, 15 litres `H_(2)`
20 litres `NH_(3)`, 10 litres `N_(2),` 30 litres `H_(2)`
20 litres `NH_(3)`, 25 litres `N_(2)`, 15 lites `H_(2)`

SOLUTION :`N_(2)(g)+3H_(2)(g)hArr 2NH_(3)(g)`
1 L of `N_(2)` reacts with 3 L of `H_(2)` to form 2 L of `NH_(3)`.
Thus, `N_(2)` is the limiting reactant.
10 L `N_(2)` will REACT with 30 L `H_(2)` to form 20 L `NH_(3).`
As actual yield is `50%` of hte expected value, `NH_(3)`formed = 10 L, `N_(2)` REACTED = 5 L,
`H_(2)` reacted = 15 L
`therefore" Mixture will contain 10 L NH"_(3),25 L N_2),`
`15L H_(2)`.
49.

In H_(3)PO_(4), which of the following is true

Answer»

`K_(a)=K_(a_(1))xxK_(a_(2))xxK_(a_(3))`
`K_(a_(1))ltK_(a_(2))ltK_(a_(3))`
`K_(a_(1))gtK_(a_(2))ltK_(a_(3))`
`K_(a_(1))=K_(a_(2))=K_(a_(3))`

SOLUTION :`H_(3)PO_(4)hArrH^(+)+H_(2)PO_(4)^(-)Ka_(1)=([H^(+)][H_(2)PO_(4)^(-)])/([H_(3)PO_(4)])""...(i)`
`h_(2)PO_(4)^(-)hArrH^(+)+HPO_(4)^(2-)K_(a_(2))=([H^(+)][HPO_(4)^(-2)])/([H_(2)PO_(4)^(-)])""...(ii)`
`HPO_(4)^(2-)hArrH^(+)+PO_(4)^(3-)K_(a_(3))=([H^(+)][HPO_(4)^(2-)])/([HPO_(4)^(2-)])""...(iii)`
`H_(3)PO_(4)hArr3H^(+)+P_(4)^(3-)K_(a)=([H^(+)]^(3)[PO_(4)^(3-)])/([H_(3)PO_(4)])""...(iv)`
Multiplying (i),(ii), (ii) and equate with (iv) `K_(a)=K_(AQ)xxK_(a_(2))xxK_(a_(3)),therefore(a)` is correct
`1^(st)` acid dissociation constant is highest because dissociation is maximum in FIRST step, less in `2^(nd)` step and MINIMUM in `3^(rd)` step because it is difficult for a negatively changed ion tolose `H_(+)` ion.
`K_(a_(1))gtK_(a_(2))gtK_(a_(3)), therefore(c)` is correct, (b) and (d) are ruled out.
50.

In H_(3)PO_(3) molecule

Answer»

P - atom is SURROUNDED by THREE - OH groups
P - atom is tetrahedrally surrounded by TWO - OH groups , one oxygen atom and one hydrogen atom
P - atom is surrounded by four - OH groups
P - atoms is surrounded by two - H atoms

Answer :B