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.

Using Slater's rule calculate the effective nuclear charge on a 3p electron in aluminium and chlorine .Explain how these results relate to the atomic radii of the two atoms.

Answer»

Solution :`ubrace(Al^(13) 1s^(2))_((N-2)) ubrace(2s^(2) 2P^(6))_((n-1))ubrace(3s^(2) 3p^(1))_((n))`

`:.` EFFECTIVE nuclear change =Z-S=13-9.5
`(Z_(eff))_Al=3.5`
Electronic CONFIGURATION of CHLORINE
`ubrace(1s^(2))_((n-2)) ubrace(2s^(2) 2p^(6))_((n-1)) ubrace(3s^(2) 3p^(5))_((n))`

`:.` Effective nuclear charge =Z-S=17=10.9
`(Z_(eff))_Cl=6.1`
`(Z_(eff))_Clgt(Z_(eff))_Al` and hence `r_(Cl) ltr_(Al)`
Discussion
2.

Which of the following reacts with ammonical cuprous chloride?

Answer»

`CH_(4)`
`C_(2)H_(2)`
`C_(2)H_(6)`
`C_(6)H_(6)`

ANSWER :B
Discussion
3.

Which of the following reactions does not show the acidic nature of ethyne?

Answer»

Acetylene reacts with SODAMIDE to form sodium acetylides.
When passed through ammoniacal CUPROUS chloride solution, a RED precipitate is formed
Acetylene reacts with chloine in the dark to form di or tetrachlorides.
Acetylene when passed THROGUH ammoniacal silver nitrate gives a white precipitate

Solution :It is an addition reaction, so it does not SHOW the acidic nature of ethyne.
Discussion
4.

what is Ideal gas equation ? Derive equation of ideal gas and give characteristic of R and its value.

Answer»

Solution :Ideal gas equation : The equation get through the COMBINATION of Boyle.s, Charle.s and Avogadro.s law is called ..Ideal Gas Equation...
Ideal gas equation : pV = nRT …..(Eq. -i)
Ideal gas equation is a relation between four variables (p, V, n, R). It describe the state of any gas, so it is called equation of state.
Derivation the equation of ideal gas :
(i) Boyle.s law : `V prop (1)/(p)` ....(constant T and n)
(II) Charles. Law : `V prop T` ....(constant p and n)
(iii) ASvogadro Law : `V prop n` ....(constant p and T)
Thus, `V prop (nT)/(p)""`....(Eq. -i)
Id standard constant = R,
`therefore V =R((nT)/(p)) ""` ....(Eq. - ii)
Thus, [pV = nRT]
This (Eq. -i) is know as ideal gas equation.
Characteristic of gas constant and value R :
R is known as gas constant.
Value of R is same for each gases. So it is known as UNIVERSAL gas constant.
Value of R depends upon the measurements unit p, V and T.
Calculation of R value :Volume of one mole of an ideal gas under STP conditions (273.15 K temperature and 1 bar pressure) is 22.710981 L `mol^(-1)`. Value of R for 1 mole of an ideal gas can be calculated under these conditions as follows :
where, p = 1 bar `= 10^(5)` PA
V = mole volume `= 22.71 mol^(-1) = 22.71xx10^(-3)m^(3)`
n = 1 mol,T = 273.15 K
pV = nRT.....(according to Eq. -5.24)
`therefore R=(pV)/(nT) ""`...(Eq. -5.26)
`therefore R=((10^(5)Pa)(22.71xx10^(-3)m^(3)))/((1mol)(273.15 K))`
`= 8.3141 Pa m^(3)mol^(1)K^(-1)`
`therefore R = 8.3141xx10^(-2)` bar L `K^(-)mol^(-1)`
`R=8.314 J K^(-1)mol^(-1)`
At STP conditions `0^(@)C` (273.15 K) and 1 atm.
pressure value of R is as under.
`R = 8.20578xx10^(-2)` L atm `K^(-1)mol^(-1)`
= 0.082 L atm `K^(-1) mol^(-1)`
Discussion
5.

When few drops of glycerol is put on powdered KMnO_(4)

Answer»

it becomes colourless
pungent smell of acrolein is produced
it is oxidised to tartronic acid
NONE of these

Solution :When a few drops of GLYCEROL is put on powdered `KMnO_(4)` it catches fire due to highly exothermic spontaneous reaction producing `CO_(2)` and water.
Discussion
6.

Whichelementsdoes notpossesneutron?

Answer»

SOLUTION :HYDROGEN.
Discussion
7.

When some of Si^(+4)in frame work silicates are replaced by Al^(+3)and an additional metal ion, it results in the formation of

Answer»

ZEOLITES
Silicones
Disilicates
Glass

Answer :A
Discussion
8.

Why are boron halides and diborane referred to as 'electron deficient compounds' ?

Answer»

SOLUTION :In these compounds, boron ATOM has an incomplete OCTET.
Discussion
9.

What is the equivalent weight of oxalate ion C_(2)O_(4)^(-2) as reducant?

Answer»

SOLUTION :`Cr_(2)O_(4)^(-2) to 2CO_(2)+2E^(-)`
Equivalent weight of `C_(2)O_(4)^(-2)ion`=
`=("Formula weight of "C_(2)O_(4)^(-2))/("No. of electrons involved in the reaction")=(88)/(2)=44`
Equivalent weight of `Na_(2)C_(2)O_(4).2H_(2)O=("Mol.Wt. of"Na_(2)C_(2)O_(4).2H_(2)O)/(2)=(175)/(2)=85`
Discussion
10.

What is Vander Waal's force ?

Answer»

Solution :It is a weak INTER ATOMIC or inter molecular FORCE of attractions existing in substances without FORMATION of any CHEMICAL bond.
Discussion
11.

Which of the following molecules represents the order of hybridisation sp^(2), sp^(2), sp, sp from left to right atoms?

Answer»

`CH_(3)- CH= CH-CH_(3)`
`HC -= C- C -=CH`
`CH_(2)= CH-CH= CH_(2)`
`CH_(2)= CH-C -=CH`

Solution :`UNDERSET(sp^(2))(CH_(2))= underset(sp^(2))(CH)- underset(sp)(C )-= underset(sp)(C H)`
Discussion
12.

What are silicones?

Answer»


Answer :POLYMERIC organo-silicon compounds Si-O -Si bonds are CALLED SILICONES.
Discussion
13.

Which of the following molecules have (-O-O-) bund i.e., peruxide bond?

Answer»

`H_(2)S_(2)O_(8)`
`H_(2)S_(2)O_(7)`
`H_(2)SO_(5)`
`H_(2)S_(2)O_(6)`

ANSWER :A::C
Discussion
14.

Which of the following reactions can produce R - CO - Ar?

Answer»

`ArCOCl + H - AR overset(AlCl_(3))rarr`
`COCl + RMg X rarr`
`R + CrO_(3) rarr`
`RCOCL + H - Ar overset(AlCl_(3))rarr`

SOLUTION :`RCOCl + Ar - H overset(AlCl_(3))rarr R - overset(O)overset(||)(C) - Ar + HCL`
Discussion
15.

Whyalknenes are more reactive than alkanes

Answer»

SOLUTION :(i)ALKENES are movereactivethan alkanesdue to thepressureof a DOUBLEBOND
(ii)The`alpha`- BONDIS stronggut the`pi-` bondis weakthe typicalreactionsof alkenesinvolvetheadditionof anelectrophilcproccedthroughfree-radicalmechanism alos .OZONOLYSISAND polymerisationare someof thecharacteristicreactionof alkenes
Discussion
16.

What is the maximum number of electrons that can be associated with the following set of quantum numbers ? n = 3, I = 1 and m = -1

Answer»

25
50
75
10

Answer :B
Discussion
17.

Which one of the alkali metals forms only the normal oxide, M_(2)O on heating in air ?

Answer»

`LI`
`NA`
`RB`
K

Answer :A
Discussion
18.

What is the maximum concentration of equimolar solutions of ferrous sulphate and sodium sulphide so that when mixed in equal volumes, there is no precipition of iron sulphide ? (For iron sulphide , K_(sp)=6.3xx10^(-18)).

Answer»

SOLUTION :`5 xx 10^(-9) MOL L^(-1)`
Discussion
19.

Which of the following methods cannot be used to prepare propane?

Answer»

REACTION of isopropylmagnesium BROMIDE with water
Reaction of n-propylmagnesium bromide with methanol
Reduction of Propene with `LiAlH_4`
Reduction of Propyne with `H_2`/Raney NI

Solution :Isolated DOUBLE bond cannot be REDUCED by `LiA//H_4`
Discussion
20.

Write the equation involved in the preparation of hydrogen peroxide from 2 - ethylanthraquinol.

Answer»

SOLUTION :`H_(2)O_(2)` can be PREPARED by autoxidation of ALKYL anthraquinol.
Discussion
21.

Which electrophile does carry out the nitration of benzene?

Answer»

SOLUTION :`NO_2^+`
Discussion
22.

When would the wavelength associated with an electron become equal to that with proton ? (Mass of electron = 9.10 xx 10^(-31) kg, Mass of proton =1.6725 xx 10^(-27)kg)

Answer»

Solution :Wave LENGTHS of electron and proton are
`lambda_(c)=(h)/(m_(e)v_(e)).lambda_(p)=(h)/(m_(p)v_(p))" But "lambda_(e)=lambda_(p)`
THEREFORE, `(h)/(m_(e)v_(e))=(h)/(m_(p)v_(p)) or m_(e)v_(e)=m_(p)v_(p)`
`V_(e)=(m_(p)v_(p))/(m_(e))=(1.6727xx10^(-27)kg)/(9.10xx10^(-31)kg)xxv_(p)=1837v_(p)`
`"Velocity of electron "=1837xx" velocity of proton."`
Discussion
23.

Whichcompoundhas lowlattice energy?

Answer»

LIH
KH
NaH
CsH

Answer :D
Discussion
24.

What isquantummechanics?

Answer»

SOLUTION :Thebranchof SCIENCETHAT takeintoaccuntthe DUALBEHAVIOUR of MATTERIS calledquantummechanics.
Discussion
25.

What mass of K_(2)Cr_(2) O_(7) is required to produce 5.0 litre CO_(2) at 75^(@)C and 1.07 atm pressure from excess of oxlaic acid? Also report the volume of 0.1N NaOH required to neutralise the CO_(2) evolved.

Answer»


ANSWER :`K_(2)Cr_(2)O_(7) = 9.18g, V = 3.746`LITRE
Discussion
26.

What is Grignard reagent? How is it prepared from ethyl bromide?

Answer»

Solution :When a.solution of haloalkane in either is treated with magnesium, we will get alkyl magnesium halide known as GRIGNARD reagent, ethyl magnesium bromide is PREPARED from ethyl bromide as:
`CH_(3) underset("Ethyl bromide") (- CH_(2) Br) + Mg OVERSET("dry ETHER") (to) underset("Grignard reagent") underset("(Or)") underset("Ethyl magnesium bromide") (CH_(3) CH_(2) Mg Br)`
Discussion
27.

The substances, which do NOT act as catalyst but when added to reaction increase the activity of the catalyst are called ________.

Answer»

inhibitors
promoters
autocatalysis
poisons

Answer :B
Discussion
28.

The set of gases causing green house effect is

Answer»

`CO_(2),CO,SO_(2),N_2`
`CO_(2),CH_(4),O_(3),NO`
`CH_(4),SO_(2),N_(2),O_2`
`CO_(2),Br_(2),N_(2),O_2`

ANSWER :B
Discussion
29.

Which of the following compounds may give white precipitate or turbidity with dilute HCI?

Answer»

`Pb(NO_(3))_(2)`
`AgNO_(3)`
`Na_(2)S_(2)O_(3)`
`CH_(3)COONa`

ANSWER :A::B::C
Discussion
30.

Which of the following compounds contains only sp^(3)-hybridized carbons ?

Answer»

Cycloalkanes
Straight CHAIN alkanes
Branched chain alkanes
Benzene

Answer :A::B::C
Discussion
31.

Water destroysgrignard reagents why?

Answer»

SOLUTION :`CH_(3)MGX= HOH toCH_(4)+ Mg (OH) X`
Waterwouldprotonatethe grignardreagent and destroythe grignardregentbecausethegrignardcarbonatomis highlynucleophilic.thiswouldforma hydrocarbon.Thereforetogrignardsolutiononlyetheris thebestsolventand WATEROR alcoholare notusedforthatpurpose.
Discussion
32.

What type of crystal defect is produced when sodium chloride is doped with MgCl_2 ?

Answer»

Solution :It is called impurity defect. A cation vacancy is produced . A substitutional SOLID solution is formed (because 2 `Na^+` IONS are replaced by one `Sr^(2+)` ion in the lattice site. )
Discussion
33.

Which of the following have the same number of electrons in outermost shell?

Answer»

Elements with ATOMIC numbers 30, 48, 80 
Elements with atomic numbers 14, 15, 16 
Elements with atomic numbers 20, 30, 50 
Elements with atomic numbers 10, 18, 26 

Answer :A
Discussion
34.

What isquantummechanics?giveitsprimaryinformation .

Answer»

Solution :Quantummeachanicsis ABRANCH of science . It takesintoaccountthisdualbehaviourof matterAnd it isbasedon theideasof wavemotion.
Quantum mechanics wasdevelopedandErwinSchrodinger.Thefoundamentalby Schrodingerand it won himthe NobelPrizein PHYSICSIN 1933.
ThisSchrodingmechanicsequation is quatecomplexand knowledgeof highermathematicsis neededto solve it.
Totalenergy( E) : The totalenergyof the systemtakesintoaccountthe kineticenergy of all thesub- atomicparticlesatractivepotentialbetweente electronsand nucleiindividually .
It isknownas wavefunctionof ATOM anddoesnotcarryanyphysicalmeaning . Itcorrespondingto allenergystate.
Discussion
35.

underset(("Dark purple almost black"))((A)) overset(Delta)rarr underset(("Green"))((B))+underset(("Black"))((C))+(D) Find the number of correct statements: (a) Compound B is K_(2)MnO_(4) (b) Compound C is MnO_(2) (c) Compound D is O_(2) (d) Compound B is paramagnetic in nature (e) Compound D has two unpaired electrons in bonding molecular orbital

Answer»


SOLUTION :`O_(2)` has 2 UNPAIRED ELECTRONS in `ABMO`.
Discussion
36.

Which of the following substances acts as an oxidising as well as a reducing agent

Answer»

`Na_(2)O`
`SnCl_(2)`
`Na_(2)O_(2)`
`NaNO_(2)`

Solution :`NaNO_(2)` (Sodium nitrite) ACTS both as oxidising as well as reducing AGENT because N atom is in +3 oxidation state in it (intermediate oxidation state).
Oxidising property:
`NaNO_(2)+2KI+2H_(2)SO_(4)toNa_(2)SO_(4)+K_(2)SO_(4)+2NO+2H_(2)O+I_(2)`
Reducing Property :
`H_(2)O_(2)+NaNO_(2)toNaNO_(3)+H_(2)O`
Discussion
37.

What is multiple bond?

Answer»

SOLUTION :DOUBLE BOND or triple bond are called MULTIPLE bond
Discussion
38.

Which of the following expression is wrong?

Answer»

`[H^(o+)] = [OVERSET(Theta)OH] = 10^(-7)` for a neutral solution at all TEMPERATURES.
`[H^(o+)] lt sqrt(K_(w))` and `[overset(Theta)OH] gt sqrt(K_(w))` for basic solution
`[H^(o+)] = [overset(Theta)OH] = sqrt(K_(w))` for a neutral solution
`[H^(o+)] gt sqrt(K_(w))` and `[overset(Theta)OH] lt sqrt(K_(w))` for an acidic solution

Solution :Statement (a) is WRONG since it is not valid all TEMPERATURE.
Discussion
39.

Which quantum number reveal information about the shape,energy,orientation and size of orbitals?

Answer»

SOLUTION :Magneticquantum number reveal INFORMATION about the SHAPE,ORIENTATION and size of orbitals.
Discussion
40.

What is the meaning of VSEPR ?

Answer»

<P>

Solution :V = Valence
S = SHELL
E = Electron
P = Pair
R = Repulsion
i.e., VSEPR MEANS (valence shell electron pair repulsion theory)
Discussion
41.

Which one in each of the following pairs is expected exhibit hydrogen bonding together? a.CH_(3)-CH_(2)-OH and CH_(3)-O-CH_(3) b. CH_(3)NH_(2) and CH_(3)SH c. CH_(3)OCH and (CH_(3))_(3)N

Answer»

Solution :a. `CH_(3)-CH_(2)OH` and H connected to O atoms.
b. S does not form HYDROGEN BONDS.
c.Both do not form hydrogen bonds because H atom is absent on O and on N.
Discussion
42.

Which of the following hydrocarbons givesame product on hydrogenation.

Answer»

2-methyl hex-1-ene & 3-Methyl hex-3 -ene
3-Ethyl hex-1-en-4-yne & 2-Methylhept 3-ene-4-eyn
3-Ethylcylcoprop-1-ene & 1,2-Dimethylcycloprop-1-ene
2-Methylbut-2-ene & 1,2-Dimethylcycloprop -1-ene

Answer :D
Discussion
43.

What is the important of Periodic table ? OR What is Periodic table according to Glenn T-Seaborg?

Answer»

Solution :The periodic table is arguably the most important concept in chemistry, both in principle and in practice. It is the everyday support for students, it SUGGESTS new avenues of research to professionals and it PROVIDES a succinct organization of the whole of chemistry.
It is a remarkable demonstration of the fact that the chemical elements are not a random cluster of ENTITIES but instead display trends and lie together in families.
An awareness of the periodic table is essential to anyone who WISHES to DISENTANGLE the world and see how it is built up from the fundamental building blocks of the chemistry, the chemical elements.
Discussion
44.

What are pesticides and herbicides ? Explain giving examples.

Answer»

Solution :Pesticides are a combination of two or more SUBTANCES. It is useful to DESTROY other insects like locusts and pests. e.g., ALDRIN and Dieldrin anesthesizers are substance used to destroy weeds.
e.g., Sodium CHLORATE : `NaClO_3`
Sodium Arsenate : `NO_3 ASO_3`
Discussion
45.

Which elements are normally not detected in an organic compound ?

Answer»

SOLUTION :CARBON & HYDROGEN.
Discussion
46.

Write the halogenation of alkene.

Answer»

Solution :(i) Common reaction : here there is breaking of `pi`-bond, Halogen is attached to the CARBON with `SIGMA`-bond. <BR>
(ii) Type of reaction : Alkene reaction with `X_(2)` (X=Cl or Br) vicinal dihalide is formed. This reaction is called electrophilic addition reaction. In this reaction unsaturated hydrocarbon is CONVERTED to saturated dihalide. Halonium ion is formed between the reaction and used as electrophilic addition reaction.
(iii) Alkene on chlorine `(Cl_(2))` and bromine `(Br_(2))` give addition product and forms vicinal dihalide and vicinal dibromide.
Example (a) Chlorination :
`underset("Ethene")(CH_(2)=CH_(2))+underset("Dichlorine")(Cl-Cl) overset("Chlorination")RARR underset("1,2-dichloro propane")(underset(Cl)underset(|)(CH_(2))-underset(Cl)underset(|)(CH_(2)))`
`CH_(3)CH_(2)=CH_(2)+Cl-Cl overset("Chlorination")rarr underset("1,2-dichloro propane")(CH_(3)-underset(Cl)underset(|)(CH_(2))-underset(Cl)underset(|)(CH_(2)))`
Example - (b) unsaturation test (Bromination) :
`underset("Ethene")(CH_(2)=CH_(2)) + underset("Bromine")underset("orange")underset("Red-")(Br_(2)) underset("Bromination")overset(C Cl_(4))rarr underset("1,2-dibromoethane")(underset(Br)underset(|)(CH_(2))-underset(Br)underset(|)(CH_(2)))`
`underset("Propene")(CH_(2)=CH_(2)) + underset("Bromine")underset("orange")underset("Red-")(Br_(2)) underset("Bromination")overset(C Cl_(4))rarr underset("1,2-dibromoethane")(CH_(3)-underset(Br)underset(|)CH-underset(Br)underset(|)(C)H_(2))`
When product forms red-orange, colour of bromene is removed and solid addition product is obtained. Bromination reaction is unsaturation test of alkene.
Discussion
47.

Thoseelementsimpartcolour to theflame on heating init , theatom ofwhichrequire lowenergyfor the ionisation(i.e.,absorb energy inthe visibleregion ofspectrum ). Theelementsof which of thefollowinggroupswillimpart colour ot theflame ?

Answer»

2
13
1
17

Solution :Theelements of group 1 (alkalimetals ) andgroup 2 (alkalineearthmetals )have 1and 2electronsrespectively in theirvalence shellsand hencelowionizationenergies. In otherwords . ELEMENTS of group 1 and 2impart colour toflamei.e.,options( a)and ( C) ARECORRECT.
Discussion
48.

Which of the following statement regarding catalyst is not true:-

Answer»

A catalyst REMAINS unchanged in composition and quantity at the END of the reaction
A catalyst can initiate a reaction
A catalyst does not ALTER the equilibrium in a reversible reaction
Catalyst are SOMETIMES very specific in respect of reaction

Answer :B
Discussion
49.

What are the major differences between metals and non-metals ?

Answer»

SOLUTION :
Discussion
50.

The weight of 1 xx 10^22 molecules of CuSO_4. 5H_2O is:

Answer»


ANSWER :4.14 G
Discussion