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.

The radius of an atom of an element is 500 pm. If it crystallizes as a face centred cubic lattice, what is the length of the side of the unit cell ?

Answer»


SOLUTION :For FCC, `r=a/(2SQRT2)` or `a=2sqrt2r=2xx1.414xx500` PM =1414 pm
2.

The radius of an atom of an element is 500 pm.If it crystallizes as a face centred cubic lattice, what is the length of the side of the unit cell ?

Answer»


Solution :For FCC ` , r = a / (2SQRT2) ORA = 2sqrt2 r = 2 xx 1.414 xx 500 "PM"= 1414 "pm"`
3.

A thin wire has a length of 21.7 cm and radius 0.46 mm. Calculate the volume of the wire to correct significant figures.

Answer»


ANSWER :`0.14 CM^(3)`
4.

The radioactive isotope of hydrogen is

Answer»

`""_(1)^(1)H`
`""_(1)^(2)H`
`""_(1)^(3)H`
`""_(1)^(0)H`

ANSWER :C
5.

The radioactive isotope of hydrogen is called ……….. And its nucleus contains ……….. Proton and ……….. Neutrons.

Answer»


ANSWER :TRITIUM, ONE, TWO
6.

The radioactive element of group 2 element is_________

Answer»

Strontium
Radium
Beryllium
francium

Answer :B
7.

Theradii of the F, F^(-) , O " and " O^(2-) are in the order ….

Answer»

`O^(2-) GT O gt F^(-) gt F`
`F^(-) gt O^(2-) gt F gt O`
`O^(2-) gt F^(-) gt F gt O`
`O^(2-) gt F^(-) gt O gt F`

ANSWER :d
8.

The radii of Na^(+) and Cl^(-) ions are 95 pm and 181 pm respectively. The edge length of NaCl unit cell is

Answer»

276 PM
138 pm
552 pm
45 pm

Solution :As NaCl has fcc lattice, edgelength
=`2times"Destance between NA^(+) and Cl^(-)ions`
=`2(r_(Na+)+r_(Cl-))=2(95+181)`pm. ltbrge552 pm.
9.

The radii of maximum probability for 3s, 3p and 3d electrons are in the order :

Answer»

`(r_("MAX"))_(3d) gt (r_("max"))_(3p) gt (r_("max"))_(3s)`
`(r_("max"))_(3d) gt (r_("max"))_(3s) gt (r_("max"))_(3p)`
`(r_("max"))_(3s) gt (r_("max"))_(3p) gt (r_("max"))_(3d)`
`(r_("max"))_(3p) gt (r_("max"))_(3s) gt (r_("max"))_(3d)`

ANSWER :C
10.

The radii of F, F^(-), O, O^(2-) are in the order

Answer»

`O^(2-) GT F^(-) gt O gt F`
`O^(2-) gt F^(-) gt F gt O`
`F^(-) O^(2-) gt F gt O`
`O^(2) gt O gt F^(-) gt F`

ANSWER :A
11.

The radii of F, F^(-) , O andO^(2-)are in the order

Answer»

`O^(2-)gtOgtF^(-)GTF`
`F^(-)GTO^(2-)gtFgtO`
`O^(2-)gtF^(-)gtOgt^(+)F`
`O^(2)gtF^(-)gtFgtO`

Answer :C
12.

The radical halogenation of 2-methylpropane gives two products: (CH_(3))_(2)CHCH_(2)X (minor) and (CH_(3))_(3)CX (major) Chlorination gives a larger amount of the minor product than does bromination, why?

Answer»

Bromine is more reactive than chlorine and is able to ATTACK the LESS reactive `3^(@)C-H`
Bromine atoms are less reactive (more selective) than chlorine, and PREFERENTIALLY attack the weaker `3^(@)C-H` bond
The methyl groups are more hindered to attack by the LARGER bromine atom.
Bromination is reversible and more STABLE `3^(@)-` alkyl bromide is formed exlusively.

Answer :B
13.

The radical halogenation of 2 - methyl propane gives two products (CH_(3))_(2)CHCH_(2)X_("(minor)") and (CH_(3))_(3)CX_("(major)"). Chlorination gives larger amount of the minor product than the bromination because

Answer»

Bromine is more REACTIVE than chlorine and is able to attack the less reactive `3^(@)C-H`
Bromine ATOMS are less reactive (more selective) than chlorine and preferentially attack the WEAKER `3^(@)C-H` bond.
The METHYL groups are more hindered to attack by the larger bromine atom
Bromination is reversible and more stable `3^(@)-` alkyl bromide is formed exclusively.

Solution :Chlorine is more reactive, less selective
Bromine is less reactive, more selective
14.

The radical halogenation of 2-methyl propane gives two products (CH_(3))_(2)CHCH_(2)X_(("minor")) and (CH_(3))_(3)CX_(("major")). Chlorination givs larger amount of the minor product than the bromination because

Answer»

BROMIDE is more reactive than chlorine and is able to attack the less reactive `3^(@)C-H`
Brominie atoms are less reactive (more selective) than chlorine and preferentially atack the weaker `3^(@)C-H` bond.
The METHYL GROUPS are more HINDERED to attack by the larger bromine atom.
Bromination is REVERSIBLE and more stable `3^(@)-` alkyl bromide is formed exlusively.

Solution :Chlorine is more reactive, less selective bromine is less reactive, more selective
15.

The radiation with highest wave number

Answer»

Microwaves 
X- rays 
I.R. - rays 
RADIOWAVES 

ANSWER :B
16.

The radial probability distribution curve of an orbital of H has '4' local maxima . If orbital has 3 angular node then orbital will be :

Answer»

7 f
8f
7d
8d

Answer :A
17.

The radial probability distribution curve obtained for an orbital wave function has 3 peaks and 2 radial nodes. The valence electron of which one of the following metals does this wave function correspond to ?

Answer»

Cu
Li
K
Na

Answer :D
18.

The radial distribution function [P(r)] is used to determine the most probable radius, which is used tofind the electron in a given orgital (dP(r))/(dr) for 1s-orbital of hydrogen like atom having atomic number Z, is (dP)/(dr) = (4Z^3)/(a_0^3) (2r-(2Zr^2))/(a_0) e^(-27 x//a_0) : Then which is the following statements is/are correct ?

Answer»

At the point of maximum value of radial distribution function `(dP(r))/(dr)=0`, one anti-node is PRESENT
Most probable RADIUS of `Li^(2+)` is `(a_0)/(3) ` pm
Most probable radius of `He^+` is `(a_0)/(2)`
Most probable radius of hydrogen atom is (a_0)

SOLUTION :(a,b,c,d) At the point of maximum value of RDF `(dP)/(dr) = 0 `
`(2r - (2Zr^2)/(a_0))= 0,r =(a_0)/(Z)`
Where Z = 3 for `Li^(2+)` and Z= 2FOR the `He^+` , Z=1 for hydrogen.
19.

The radial distribution function [P(r)] is use to determine the most probable radius, which is used to find the electron in a given orbital (dP(r))/(dr) for 1s-orbital of hydrogen like atom having atomic number Z, is (dP)/(dr) = (4Z^(3))/(a_(0)^(3))(2r-(2Zr^(2))/(a_(0)))e^(-2Ze//a_(0)). Then which of the following statements is/are correct

Answer»

At the point of maximum value of radial distribution function `(dP(R))/(dr) = 0`, ONE antinode is PRESENT
Most probable radius of `LI^(2+)` is `(a_(0))/(3)` pm
Most probable radius of `He^(+)` is `(a_(0))/(2)` pm
Most probable radius of hydrogen atom is `a_(0)` pm

Answer :A::B::C::D
20.

The R/S conifiguration of these compounds are respectively

Answer»

R,R,R
R,S,R
R,S,S
S,S,S

Answer :A
21.

The questionsgiven belowcontainstatement -1 (Assertion ) andstatement -2 (Reason ) . Ithas fouroptions(a), (b) , ( c) and (d ) out ofwhich ONLYONE iscorrect . Choosethe correctoptionas.Statement -1 . Of all theelementsheliumhas thehighestvalue offirstionizationenthalpy Statement-2Heliumhas themostpositiveelectrongainenthalpyof all theelement s.

Answer»

Statement -1 ISTRUE Statement-2 isTrue, Statement-2 iscorrectexplanationfor Statement -5
Statement -1 isTrueStatement-2 isTrue , Statement-2 is nota correctexplanationfor Statement -5
Statement -1 isTrueStatement-2 is False
Statement -1 is FalseStatement-2 isTrue

SOLUTION :CORRECTSTATEMENT -2 . Heliumis thesmallestinertgas .
22.

The questionsgiven belowcontainstatement -1 (Assertion ) andstatement -2 (Reason ) . Ithas fouroptions(a), (b) , ( c) and (d ) out ofwhich ONLYONE iscorrect . Choosethe correctoptionas. Statement - 1. The ionicsize ofO^(2-) is biggerthan that ofF^(-)ion. Statement -2. O^(2-) and F^(-) are isoelectronic ions.

Answer»

Statement -1 ISTRUE Statement-2 isTrue, Statement-2 iscorrectexplanationfor Statement -3
Statement -1 isTrueStatement-2 isTrue , Statement-2 is NOTA correctexplanationfor Statement -3
Statement -1 isTrueStatement-2 is False
Statement -1 is FalseStatement-2 isTrue

Solution :CORRECTEXPLANATION .` O^(2-)` hashigher negativechargethatn `F^(-)`
23.

The questionsgiven belowcontainstatement -1 (Assertion ) andstatement -2 (Reason ) . Ithas fouroptions(a), (b) , ( c) and (d ) out ofwhich ONLYONE iscorrect . Choosethe correctoptionas. Statement -1. The ionicradiifollowsthe order : I^(-)lt I lt I^(+) Statement -2 . Smallerthe valueof z//elargerthe sizeof the species .

Answer»

Statement -1 isTrue Statement-2 isTrue, Statement-2 iscorrectexplanationfor Statement -4
Statement -1 isTrueStatement-2 isTrue , Statement-2 is nota correctexplanationfor Statement -4
Statement -1 isTrueStatement-2 is False
Statement -1 is FalseStatement-2 isTrue

Solution :Correctstatement -1. Theionicradii followsthe ORDER `I^(+)LG I LT I^(-)`
24.

The R and S configuration for each sterogenic centre in this from top to bottom?

Answer»

R.R.R
R.S.S
R.S.R
S.S.R

Answer :3
25.

The questionsgiven belowcontainstatement -1 (Assertion ) andstatement -2 (Reason ) . Ithas fouroptions(a), (b) , ( c) and (d ) out ofwhich ONLYONE iscorrect . Choosethe correctoptionas. Statement - 1 . The elements having 1 s^(2) 2s^(2)2p^(6)3s^(2) and1s^(2)2s^(2) configurationbelongto the samegroup Statement-2 . Bothhave samenumberof electronselectronsin the valenceshell.

Answer»

Statement -1 ISTRUE Statement-2 isTrue, Statement-2 iscorrectexplanationfor Statement -2
Statement -1 isTrueStatement-2 isTrue , Statement-2 is NOTA correctexplanationfor Statement -2
Statement -1 isTrueStatement-2 is False
Statement -1 is FalseStatement-2 isTrue

Solution :Correctstatement -1 . THEELEMENTWITH E.C`1s^(2)2S^(2)2p^(6)3s^(2) ` belongs to group 2 but theelementwith E.C. `1s^(2)2s^(2)` (i.e.,helium ) is aninertgas andhencebelongsto group 18.
26.

The questionsgiven belowcontainstatement -1 (Assertion ) andstatement -2 (Reason ) . Ithas fouroptions(a), (b) , ( c) and (d ) out ofwhich ONLYONE iscorrect . Choosethe correctoptionas.Statement -1 . Sixthperiodis the longestperiodin the periodictable. Statement -2 . Sixthperiodinvolvesthe fillingof all theorbitalsof the sixthenergylevel

Answer»

Statement -1 isTrue Statement-2 isTrue, Statement-2 iscorrectexplanationfor Statement -1
Statement -1 isTrueStatement-2 isTrue , Statement-2 is NOTA correctexplanationfor Statement -1
Statement -1 isTrueStatement-2 is False
Statement -1 is FalseStatement-2 isTrue

Solution :CORRECT statement -2 Sixthperioddoes not INVOLVE thefillingof all theorbitalsof the sixthenergylevel(i.e.,6s 4f, 5d 6 p- orbitals are FILLED )
27.

The questions given below consists of an assertion and the reason. Choose the correct option out of the choices given below each question. Assertion (A): If BOD level of water in a reservoir is more than 5 ppm it is highly polluted. Reason(R): High biological oxygen demand means high activity of bacteria in water

Answer»

 Both (A) and R are CORRECT and (R) is the correct EXPLANATION of (A)
Both (A) and R are correct and (R) is not the correct explanation of (A)
Both (A) and R are not correct
(A) is correct but( R) is not correct

Answer :d
28.

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. List if any of these combination (s) has/have the same energy: (i) n = 4, l = 2, m_(l) = -2, m_(s) = -1//2 (ii) n = 3, l = 2, m_(l) = -1, m_(s) = +1//2 (iii) n = 4, l = 1, m_(l) = 0, m_(s) = +1//2 (iv) n = 3, l = 2, m_(l) = -2, m_(s) = -1//2 (v) n = 3, l = 1, m_(l) = -1, m_(s) = +1//2 (vi) n = 4, l = 1, m_(l) = 0, m_(s) = +1//2

Answer»

Solution :The ORBITALS occupied by the ELECTRONS are (i) 4D (ii) 3d (iii) 4P (iv) 3d (v) 3p (VI) 4p
Their energies will be in the order:(v) `lt (ii) = (iv) lt = (iii) lt (i)`
29.

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. If any of these combination(s) has/have the same energy lists. (i) n = 4, l = 2, m_l = -2, m_s = -1/2 (ii) n = 3, l = 2, m_l = 1, m_s = +1/2 (iii) n = 4, l = 1, m_l = 0, m_s = +1/2 (iv) n = 3, l = 2, m_l = -2, m_s = -1/2 (v) n = 3, l = 1, m_l = -1, m_s = +1/2 (vi) n = 4, l = 1, m_l =0 , m_s = +1/2.

Answer»

Solution :
`:. (V) < (ii) = (iv) < (III) = (VI) < (i)`
`:. 3p < 3d = 3d < 4P = 4p < 4d.`
30.

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. Do any of these combination have same energy. {:(1.,n=4,l=2,m_(l) = -2,m_(s)=-1//2,),(2.,n=3,l=2,m_(l) = 1,m_(s) = +1//2,),(3.,n=4,l=1,m_(l) = 0,m_(s) = +1//2,),(4.,n=3, l=2,m_(l) = -2,m_(s) = -1//2,),(5.,n=3,l=1,m_(l) = -1,m_(s) = +1//2,),(6.,n=4,l=1,m_(l) = 0,m_(s) = +1//2,):}

Answer»

SOLUTION :The order or increasing energies is :
`5<2 =4<3 = 6<1 `
2 and 4 electrons have the same ENERGY, similarly 3 and 6 electrons also have same energy
31.

The quantum numbers of four electrons (e_(1) " to " e_(4)) are given below : {:(,n,l,m,s,,,n,l,m,s),(e_(1),3,0,0,+1//2,,e_(2),4,0,0,+1//2),(e_(3),3,2,2,-1//2,,e_(4),3,1,-1,+1//2):} Correct order of decreasing energy of these electrons is

Answer»

`e_(4) gt e_(3) gt e_(2) gt e_(1)`
`e_(2) gt e_(3) gt e_(4) gt e_(1)`
`e_(3) gt e_(2) gt e_(4) gt e_(1)`
`e_(1) gt e_(4) gt e_(2) gt e_(3)`

Answer :C
32.

The quantum numbers n=2, l=1 represent

Answer»

<P>1S ORBITAL
2s orbital
2p orbital
3d orbital

Solution :l=1 is for p orbital
33.

The quantum number which tells about the orientation of different orbitals of an atom is called........

Answer»

SOLUTION :MAGNETIC QUANTUM NUMBER
34.

The values of quantum numbers n, 1 and m for the fifth electron of boron is

Answer»

rotation of the electron in clockwise and anticlockwise direction RESPECTIVELY.
rotation of the electron in anticlockwise and clockwise direction respectively.
magnetic moment of the electron POINTING up and down respectively.
two quantum MECHANICAL spin states which have no CLASSICAL analogue.

Solution :spin quantum number indicates the POSSIBLE Elements
35.

The quantum number which may be designated by s,p,d and f instead of number is

Answer»

<P>n
l
`m_1`
`m_s`

SOLUTION :l=0 is s,l=1 is p and l=2 is d and so on hence, s,p,d may be USED instead of no
36.

The quantum number which tells about the angular momenta of the different electrons present in an atom is called........

Answer»

SOLUTION :AZIMUTHAL QUANTUM NUMBERS
37.

The quantum number which explain the line spectra observed as doublets in case of hydrogen and alkali metals and doublets & triplets in case of alkaline earth metals is

Answer»

Spin
Azimuthal
Magnetic
Principle

Answer :A
38.

The quantum number which is equal for all the d-electrons in an atom is

Answer»

l
m
s
n

Answer :A
39.

The quantum number of sixelectrons are givenbelow,Arrangethemin orderof increasingenergies . If anyofthesecombinationhashave thesameenergylists:(1) n-4,l=2 , m_(1)= 2m_(1) = (1)/(2) (2)n=3, l = 2, m_(1)= 1 ,m_(s) = (1)/(2) (3 ) n=4, l = 1 , m_(1) = =0 m_(s ) = (1)/(2) (4 )n=3: l= 2 m_(1)= - 2 m_(s ) = - (1)/(2) (5 )n=3, l = 1,m_(1)= - 1m_(s ) = (1)/(2) (6)n=4, l = 1, m_(1)= 0m_(s ) = (1)/(2)

Answer»

SOLUTION :(1)L =2so dand n= 4 so4dsubshell
(2)l=2so dand n=3 so3dsubshell
(3 )l =1so p andn=4so 4p
(5 )l =1 sop andn= 3 so 3p
(6)l =1so p andn=4so 4p
This4d3d , 3d4parrange as perenergythan
(5) `3p(4 ) 3d = 2 (3d)lt (6) 4p= (3) 4p lt (1)4D (5 )lt (4) = (2)lt (6)= (3) lt (1) to`energyincreases(2) ,(3) (4) and(6) has sameenergy .
40.

The quantum number not obtained from the Schrodinger.s wave equation is

Answer»

n
l
m
s

Answer :D
41.

The quantium number of four electrons (e_1to e_4) are given below The correct order of decreasing energy of these electrons is

Answer»

`e_4 gt e_3 gt e_2 gt e_1`
`e_2 gt e_3 gt e_4 gt e_1`
`e_3 gt e_2 gt e_4 gt e_1`
`e_1 gt e_3 gt e_4 gt e_2`

Solution :N= l VALUES DESCENDING order.
42.

The quantity that does not change for a sample of a gas in a sealed rigid container when. It is cooled from 120^(@)C to 90^(@)C at constant volume is:

Answer»

average energy of the molecule
pressure of the gas
density of the gas
average SPEED of the MOLECULES

ANSWER :c
43.

The quantity of heat required to raise the temperature of 1 gm of water by 1^@C is ____

Answer»

SOLUTION :1 CALORIE
44.

The quantim mechanical treatment of the hydrogen atom gives the energy vale:E_n=(-13.6)/(n^(2))eV "atom"^(-1)(i) use thios expression to find /_\Ebetween=3 and n=4(ii) Calcuilate the wavelength corresponding to the above transition.

Answer»

Solution :(i) When n=3
`E_3=(-13.6)/(3^(2))=(-13.6)/(9)=-1.511eV "atom"^(-1)`
When n=5`E_4=(-13.6)/(4^(2))=(-13.6)/(16)=-0.85 eV "atom"^(-1)`
`/_\E=E_4-E_3`
`=-0.85-(-1.511)=+0.661eV "atom"^(-1)`
`/_\E=E_3-E_4`
`=-1.511-(-0.85)`
`=-0.661 eV " atom"^(-1)`
(ii) WAVE length=`gamma `
`/_\E=(hc)/(gamma)`
`therefore gamma=(hc)/(/_\E)`
`/_\E=0.661xx1.6xx10^(-19)J`
`=1.06xx10^(-19)j`
h=planck.s constant=`6.626xx10^(-34)JS^(-1)`
`c=3xx10^(8)m/s`
`therefore gamma=(6.626xx10^(-34)xx3xx10^(8))/(1.06xx10^(-19))`
`=1875xx10^(-6)m.`
45.

The quality of diesel is expressed in terms of

Answer»

OCTANE NUMBER
decane number
IGNITION number
cetane number

ANSWER :D
46.

The pyknometric density of sodium chloride crystal is 2.165xx10^3 " kg m"^(-3) while its X-ray density is 2.178xx10^3 " kg m"^(-3) . The fraction of the unoccupied sites in sodium chloride crystal is

Answer»

5.96
`5.96xx10^(-2)`
`5.96xx10^(-1)`
`5.96xx10^(-3)`

Solution :MOLAR volume from pyknometric DENSITY =`M/(2.165xx10^3)m^3`
Molar volume from X-ray density `=M/(2.178xx10^3)m^3`
`THEREFORE` Volume unoccupied `=M/10^3(1/2.165-1/2.178)m^3=(0.013Mxx10^(-3))/(2.165xx2.178)`
`therefore` Fraction unoccupied `=((0.013Mxx10^(-3))/(2.165xx2.178))//((Mxx10^(-3))/2.165)=5.96xx10^(-3)`
47.

The pyknometric density of sodium chloride crystal is 2.165times10^(3)kg"" m^(-3)while its X-ray density is 2.178times10^(3)kg"" m^(-3). The fraction of unoccupiedsites in sodium chloride crystal is

Answer»

`5.96times10^(-3)`
5.96
`5.96times10^(-2)`
`5.96times10^(-1)`

Solution :Pyknometric DENSITY = Observed density
`=2.165 times10^(3)KG"" m^(-3)`
X-ray density = Calculated density
=`2.178 times10^(3) kg"" m^(-3)`
DECREASE indensity
`=(2.178times10^(3)-2.165times10^(3))kg"" m^(-3)`
=`(0.013 times10^(3))kg"" m^(-3)=13kg"" m^(-3)`
Fraction of unoccupied sites
=`("Decrease in density")/("Calculated density")`
=`(13kg"" m^(-3))/(2.178times10^(3)kg"" m^(-3))=5.96times10^(-3)`
48.

The pyknometric density of sodium chloride crystals is2.165 xx 10^(3) kg m^(-3)while X -ray density is2.178 xx 10^(3)kg m^(-3) . Thefraction of the unoccupied sites in sodium chloride crystal is

Answer»

5.96
`5.96 xx 10^(-2)`
`5.96 xx 10^(-1)`
` 5.96 xx 10^(-3)`

Solution :MOLAR VOLUME from pyknometric density
` = M/(2.165 xx 10^(3)) m^(3)`
Molar volume from X-ray density
` M/(2.178 xx 10^(3)) m^(3)`
Volume unoccpied
`M/10^(3) ( 1/(2.165) - 1/(2.178))m^(3) = (( 0.013 M xx10^(-3))/(2.165 xx 2.178))//((M xx 10^(-3))/2.165) = 5.96 xx 10^(-3)`
49.

The pyknometer density of NaCl crystal is 2.165xx10^(3)kg m^(-3) while its X - rays density is 2.178xx10^(3)kg m^(-3). The fraction of the unoccupied sites in NaCl crystal is

Answer»

`5.968`
`5.96xx10^(-2)`
`5.96xx10^(-3)`
`5.96xx10^(-4)`

SOLUTION :Molar volume from pyknometer density `= (M)/(2.165xx10^(3))m^(3)`
Molar volume from X - RAY density `= (M)/(2.178xx10^(3))m^(3)`
`therefore` Volume unoccupied `=((1)/(2.165)-(1)/(2.178))(M)/(10^(3))m^(3)`
Fraction unoccupied `=((1)/(2.165)-(1)/(2.178))//(1)/(2.165)`
`= 5.96xx10^(-3)`
50.

The purpose of chemistry can be understood and described by...........

Answer»

FUNDAMENTAL PARTICLES
atoms
molecules
all of the above

Answer :A::B::C::D