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.

What sorts of informations can you draw form the following reaction : (CN)_(2)(g)+2OH^(-)(aq)rarrCN^(-)(aq)+CN^(-)(aq)rarrCN^(-)(aq)+CN^(-)(aq)+CNO^(-)(aq)+H_(2)O(l)

Answer»

Solution :Let x be the O.N of C `therefore` O.N of c in cayanogen `(cn)_(2)=2(x-3)=0 or x=+3`
O.N of C in cyanide ion `CN^(-)=x-3=-1 or x =+2`
O.N of C in cyantate ion CND = x-3 -2 =- 1 or x=-4
The following four information can be drawn from the above reaction
(i) the reaction in volved decompostion of cyanogen `(CN)_(2)` to +2 in `CN^(-)` ion and INCREASES from +3 in `(CN)_(2)` to +4 is `CNO^(-)` ion of C thus cyangoen is simultaneously reduced to caynide ion andd oxidised to cyantate ion
(III) it is an example of a redox reaction and a disportination in particular (IV) cyanogen is a pseudohalogen (behave like halogens) while cyanide ions is a peseudhalide ion (behave like halide ion)
Discussion
2.

When 50 grams of sulphur was burnt in air, 4% of the impure residue is left over. Calculate the volume of air required at STP containing 21% of oxygen by volume.

Answer»

Solution :Weight of sample of SULPHUR taken = 50 g
PERCENTANGE of impurity `=4%`
Weight of impurity in sample `=(4xx50)/(100)=2gr`
Weight of sulphur `=50-2=40" grams"`
Combustion of sulphur gives sulphurdioxide
`S+O_(2)rarrSO_(2)`
`"1 mole of S"-="1 mole of"O_(2)`
`"32 grams of S"="22.4 L of "O_(2)"at STP"`
`"48 grams of S"=?`
Volume of oxygen required at STP `=(48)/(32)xx22.4=33.6L`
`"21 L of "O_(2)" is present in 100 L of air"`
`"33.6 of "O_(2)" present in ?"`
`"Volume of air required at STP"=(33.6)/(21)xx100=160L`
Discussion
3.

Which of the following compound can give test with Tollen's reagent and yellow precipitate with iodinein NaOH ?

Answer»

`CH_(2)=O`
`CH_(3)-CH=O`
`CH_(3)-CH_(2)-CH=O`
`CH_(3)-underset(O)underset(||)(C)-CH_(3)`

Solution :ACETALDEHYDE is the only aldehyde which GIVES HALOFORM test.
Discussion
4.

Write note on Williamson's Synthesis

Answer»

Solution :Williamson.s SYNTHESIS: Haloalkanes when boiled with ·SODIUM alkoxide GIVES the corresponding ether.
`underset("Bromo ETHANE ")(CH_(3)-CH_(2))Br+underset("Sodium ethoxide ")(CH_(3)CH_(2)ONa) rarr CH_(3)-CH_(2)-underset("DIETHYL ether ")O-CH_(2)-CH_(3)+NaBr`
Discussion
5.

Which of the following compounds contain(s) no covalent bond(s) ?KCl, PH_3 , O_2 , B_2H_6, H_2SO_4

Answer»

`KCL, B_2H_6`
`KCl, H_2SO_4`
`KCl`
`KCl , B_2H_6`

SOLUTION :KCl having IONIC BOND
Discussion
6.

Which of the following statement is incorrect

Answer»

Liquid having high viscosity flows quickly
Rain DROP assumes spherical SHAPE due to the surface tension of water
GLASS is a super cooled which appears like a SOLID
Standard boiling point of a liquid is LESS than its normal boiling point .

Answer :A
Discussion
7.

Which is the structural formula of isobutyl group?

Answer»

`CH_(3)- CH_(3)- underset(underset(CH_(3))(|))(CH)-`
`CH_(3)-underset(underset(CH_(3))(|))(CH)-CH_(2)-`
`CH_(3)- underset(underset(CH_(3))(|))OVERSET(overset(CH_(3))(|))(C )-`
`CH_(3)-underset(underset(CH_(3))(|))overset(overset(CH_(3))(|))(C )- CH_(2)-`

Answer :B
Discussion
8.

Which one of the following will undergo meta substitution on mono chlorination?

Answer»

CHLORO benzene
phenol
ETHYL BENZOATE
ethoxybenzene

SOLUTION :ethyl benzoate
Discussion
9.

Which one of the halogn is prepared by only electrolysis method

Answer»

`Cl_(2)`<BR>`Br_(2)`
`F_(2)`
`I_2`

Answer :C
Discussion
10.

Write the formulae of the first 5 members of homologous series starting with the underlined CH_3COCH_3

Answer»


ANSWER :`CH_3COCH_2CH_3, CH_3COCH_2CH_2CH_3, CH_3CH_2COCH_2CH_3, CH_3CH_2COCH_2CH_2CH_3`
Discussion
11.

Which statement is true about Becl, in its vapour state ?

Answer»

Each Be is LINKED with two Cl
Each Be-Cl bond strength is EQUAL
There are THREE Be-Cl - Be type of linkage
Each Be is linked with three Cl

Solution :`BeCl_(2)` invapour state forms a dimer having chloro-chloro (Cl-Cl) BRIDGE
Discussion
12.

When Zn metal is added to CuSO_(4) solution, Cu is precipitated, it is due to

Answer»

Reduction of Zn
Reduction of `CU^(2+)`
HYDROLYSIS of `CuSO_(4)`
Reduction of `SO_(4)^(2-)`

Answer :B
Discussion
13.

Which of the following is not hydrolysed ?

Answer»

`AsCl_(3)`
`PF_(3)`
`SbCl_(3)`
`NF_(3)`

Solution :Neither N nor F has d-orbitals to accept electrons donated by water for hydrolysis.
Discussion
14.

Which of the following conclusions could not be derived from Rutherford’s a-particle scattering experiement ?

Answer»

Most of the space in the atom is empty.
The radius of the atom is about `10^(-10)` m while that of nucleus is `10^(-15)` m.
Electrons move in a circular path of FIXED energy CALLED orbits.
Electrons and the nucleus are HELD together by electrostatic forces of attraction.

Solution :oncept of electrons move in a circular path of fixed energy called orbits was put forward by Bohr and not derived from R utherford.s scattering experiment. Out of a large NUMBER of circular orbits theoretically possible AROUND the nucleus, the electron revolve only in those orbits which have a tired value of energy. So, these orbits are called energy level or stationary states
Discussion
15.

What is free expansion ?

Answer»

<P>

Solution :Expansion of a GAS in vacuum `(p_(ex) = 0)` is called FREE expansion.
Discussion
16.

Which of the following alcohols is the least soluble in water?

Answer»

Ethanol
1-Propanol
1-Butanol
1-Pentanol

Solution :Solubility of ALCOHOL in water DECREASES with increase in their molecular MASSES.
Discussion
17.

Which of the following statement is wrong

Answer»

The product of uncertainty in postion and uncertainty in moments is greater than or equal to `h/(2pi)`
If the position of a particle is MEASURED accurately, there will be more error in MEASUREMENT of momentum
If the momentum of a particle is measured accurately, there will be more error in measurement of position
The position and VELOCITY of a particle can be simultaneously KNOWN with accuracy

Solution :`Deltax xx Delta V ge h/(4pi m)`
Heisenbergs uncertianity principle
Discussion
18.

When the pressure of 2 litres of O_2 gas isdoubled and its temperature is also doubled from 300K to 600K, the final volume of the gas is

Answer»

4 lit
20 lit
40 lit
2 lit

SOLUTION :`(P_1V_1)/(n_1T_1) = (P_2V_2)/(n_2T_2) , (P XX 2)/(300) = (2P xx V_2)/(600) = V_2 = 2L`.
Discussion
19.

The value of ........ is less for D_2Ocompared to that of H_2O

Answer»

density `(GM^(-1))` at `20^@C`
boiling point
DIELECTRIC constant at `20^@C`
latent heat vapourisation `(j.g^(-1))`

Solution :Dielectric constant
Discussion
20.

Which of the following has the maximum mass (a) 20 g of phosphorus (b) 5 moles of water (c) 12 xx 10^(24) atoms of hydrogen ?

Answer»


Solution :(a) 20 gram of phosphorus = 20.0 G
(b) 1 gram mole of WATER = 18.0 g
5 gram molesmoles water `= 18.0 xx 5 = 90.0 g`
(C) `6.022 xx 10^(23)`atoms of hydrogen = 1.0 g
`12.0 xx 10^(24)`atoms of hydrogen `= (12.0 xx10^(24))/(6.022xx10^(23))=19.93g`
5 moles of water have MAXIMUM mass = 90.0 g.
Discussion
21.

The raw materials used in the manufacture of Na_2CO_3 by Solvay process are:

Answer»

SOLUTION :The RAW MATERIALS are NACL, `CaCO_3and NH_3` .
Discussion
22.

Turpentine oil can be purified by:

Answer»

STEAM DISTILLATION
VACUUM distillation
SIMPLE distillation
Fractional distillation

ANSWER :A
Discussion
23.

What is working standard?

Answer»

Solution :At the time of experiment, the solution with REQUIRED concentration is PREPARED by DILUTING the stock solution. Is diluted solution is usually called working STANDARD
Discussion
24.

Which of the following statements is not correct for a nucleophile ?

Answer»

AMMONIA is a nuelcophile
Nucleophiles attack low `e^(-)` density sites
Nucleophiles are not ELECTRON seeking
NUCLEOPHILE is a LEWIS ACID

Answer :D
Discussion
25.

Which species does not exhibit a plane of symmertry ?

Answer»




SOLUTION :
Discussion
26.

What is the molality of a semimolar NaCl solution if the density of the solution is 1.16 g cm^(-3)?

Answer»


ANSWER :0.44 m
Discussion
27.

Which of the following are reversible reactions ?

Answer»

` AgNO_(3) (AQ) + NaCl (aq) to`
`AgCl (s) + NaNO_(3) (aq)`
`KNO_(3) (aq) + NaCl (aq) to `
` KCl (aq) + NaNO_(3)`
` BaCl_(2) (aq) + Na_(2) SO_(4) to`
`BaSO_(4) (s) + 2 NaCl (aq) `
`AgCl (s) + Water to Ag^(+) (aq) + Cl^(-) (aq)`

SOLUTION :In (B), ions are in equilibrium . In (d) , ions are in equilibrium with the undissolved salt .
Discussion
28.

What is energy of Hydrogen bond ?

Answer»

SOLUTION :ENERGY of H - BOND is 10 to 100 kJ `MOL^(-1)`.
Discussion
29.

Which of the following acid radical does not produce white ppt. with Pb(OAc)_(2) solution?

Answer»

`Br^(-)`
`S_(2)O_(3)^(2-)`
`CO_(3)^(2-)`
None of these

Answer :D
Discussion
30.

Total mole fraction of solution is ........... .

Answer»




ANSWER :ONE
Discussion
31.

When a certain metal was irradiated with a light of frequency 3.2 xx 10^(16) Hz, the photoelectrons had twice the kinetic energy as emitted when the same was irradiated with light of frequency 2.0 xx 10^(16)Hz. Calculate the threshold frequency (v_(0)) of the metal.

Answer»

Solution :Kinetic energy of photoelectrons emitted `= hv - hv_(0) = h (v - v_(0))`
In 1ST case, `(K.E.)_(1) = h (3.2 XX 10^(16) - v_(0))`
In 2ND case, `(K.E.)_(2) = h (2.0 xx 10^(16) - v_(0))`
But `(K.E.)_(1) = 2 (K.E.)_(2) ("Given") :. h (3.2 xx 10^(16) - v_(0)) = 2h (2.0 xx 10^(16) - v_(0))`
or `v_(0) = 4 xx 10^(16) - 3.2 xx 10^(16) = 0.8 xx 10^(16) = 8 xx 10^(15) HZ`
Discussion
32.

What happens when propene undergoes ozonolysis?

Answer»

SOLUTION :When PROPENE is added to ozone MOLECULE gives propene ozonide. Further on HYDROLYSIS of ozonide by ` H_(2) `O/Zn gives Acetaldehyde and formaldehyde.
Discussion
33.

What happens when a borax solution is acidified ? Write a balanced equation for the reaction.

Answer»

SOLUTION :`Na_2 B_4 O_7 + 2HCL + 5 H_2 O to 2NaCl + 4H_3 BO_3`
Discussion
34.

What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4 g of carbon dioxide contained in a 9 dm^(3) flask at 27^(@)C ?

Answer»

Solution :Calculation of Partial Pressure :
Methane `(CH_(4))=3.2` gm
Molecular mass of methane = 16 g `mol^(-1)`
MOLE of `CH_(4)=(3.2)/(16)=0.2 = n`
`V=9 dm^(3)=9xx10^(-3)m^(-3)`
`T=(27+273)=300K`
`R=8.314 p_(a)m^(3)K^(-1)mol^(-1)`
If partial pressure of methane is `p_(SH_(4))` then,
`p_(CH_(4))=(n)/(V)RT`
`= ((3.2 mol)(8.314 p_(a)m^(3)K^(-1)mol^(-1))(300 K))/(16xx9xx10^(-3)m^(3))`
`= 55.43xx10^(3)p_(a)=5.543xx10^(4)p_(a)`
Calculation of Partial Pressure of `CO_(2)` :
Weight of `CO_(2)(m)=4.4 g`
Molecular mass of `CO_(2)=12+2(16)=44g mol^(-1)`
Mole of `CO_(2)(n)=(4.4g)/(44 g mol^(-1))=0.1` mol
If Partial Pressure of `CO_(2)` is `p_(CO_(2))` then,
`p_(CO_(2))=(n)/(V)RT`
`= ((0.1 mol)(8.314 p_(a)m^(3)K^(-1)mol^(-1))(300 K))/(9xx10^(-3)m^(3))`
`= 27.713xx10^(3)p_(a)=2.7713xx10^(4)p_(a)`
`p_("TOTAL")=(p_(CO_(2))+p_(CH_(4)))`
`= (2.7713xx10^(4)+5.543xx10^(4))p_(a)`
`= 8.314xx10^(4)p_(a)`
OR
`p_("total")=(p_(CH_(4))+p_(CO_(2)))`
`= ((0.2+0.1)(8.314 p_(a)m^(3)K^(-1)mol^(-1))(300K))/(9xx10^(-3)m^(3))`
`= 8.314xx10^(4)p_(a)`
Discussion
35.

Which of the following gases are heavier than air ?

Answer»

Argon
Fluorine
Neon
Moist air

Solution :`Ar` and `F_(2)` are HEAVIER than air (compare their MOLECULAR MASSES with that of air. Take molecular MASS of air to be 30 (approx).
Discussion
36.

Which of the following statement is wrong about Lother - Meyer's plot between atomic volume against atomic weight ?

Answer»

The most strongly electropositive ALKALI METALS occupy packs on the curve.
The stongly electronegative HALOGEN atoms occupy ascending positions on the curve
The LESS strongly electropositive alkaline EARTH metals occupy desending positions on the curve
All are correct

Answer :D
Discussion
37.

What is Pneumoconiosis ? How does it our ?

Answer»

SOLUTION :PNEUMOCONIOSIS is a disease of lungs such as LUNG cancer, bronchial ASTHMA, chronic bronchitis, etc. It is caused by small sized PARTICULATES which enter into lung through nose and provide a large surface area for adsorption of carcinogenic compounds such as polynuclear hydrocarbons, asbestos, etc
Discussion
38.

What is the formula of a compound in which the element Y forms ccp lattice and atoms X occupy 1/3rd of tetrahedral voids.

Answer»


Solution :Suppose no. of ATOMS Y present in the packing =n
Then, TETRAHEDRAL voids = 2n
Atoms X present in the tetrahedral voids=`1/3xx2n ="2n"/3`
`THEREFORE` Ratio of X:Y =`"2n"/3:n=2/3:1=2:3`
Hence, the FORMULA is `X_2Y_3`
Discussion
39.

What is critical temperature ?

Answer»

Solution : ..What DENSITY of LIQUID and vapours BECOMES the same the clear BOUNDARY between liquid and vapours disappears. This temperature is called critical temperature...
Discussion
40.

What is Aromatic ? Explain with suitable examples.

Answer»

Solution :Benzene was considered as parent .aromatic. compound. Now the name is applied to all the ring SYSTEM whether or not having benzene ring, possessing following characteristics.
(a) Requirements for aromatic character in compound :
(i) Compound must havr cyclic (ring) structure.
(ii) Cyclic compound must have all atoms in one planer structure.
(iii) COMPLETE delocalisation of the `pi` electronsin the ring.
(iv) Presence of `(4n+2)pi` electrons in the rinf where .n. is an inetger (n=0, 1, 2,...). This is often referred to as Huckel Rule.
(b) Huckel.s rule for aromaticity : If the number of electrons in planar cyclic compound equals to (4n+2), then these compounds possess aromatic PROPERTIES, (aromaticity) where n = number of cyclic structures, (4n+2) = total delocalized ELECTRON of atoms present in aromatic ring).
(c) Aromatic hydrocarbon compounds :
(i) Benzene is aromatic in nature.
Number of rings in benzene = n =1
NUmber of double bonds in benzene = 3
so, number of `pi2(p)` electrons = 6
`therefore` According to Huckel rule, if (4n+2) `pi` electrons are present in structure then it is considered as aromatic.
So for benzene , n=1 and (4n+2) = 4(1) + 2 = 6, so benzen obeys Huckel rules and benzene is aromatic in nature and it possess aromatic characteristics.

(ii) Cyclopentadienyl anion aromatic in nature.
According to Huckel rule, n = 1 and hence (4n+2) = 6
In cyclopentadienail anion two double bond have `2 xx 2 = 4pi` + two lone `pi` electrons, so it is aromatic in nature.

(iii) Cycloheptatrienyl cation is aromatic in nature.
Number of ring = n = 1
`therefore (4n+2) = 6`

In this compound three double bonds are present, so no. of `pi` electrons `= (3 xx 2) = 6`. So it follows Huckel rule, so cycloheptatriene, n = 1(4n+2)=6, cation is aromatic in nature. It possess positive charge `sp^(2)` carbon so it also possess planarity.
(iv) Nepthalene is aromatic in nature.

Number of ring = n= 2
It having five double bonds so no. of `pi` electrons `= (5 xx 2) = 10` electrons
Napthalene follows Huckel rules and so it is aromatic innature.
(v) Anthrecene and Phenanathrene are aromatic compounds.
Discussion
41.

Which is the correct order of electron gain enthalpy ?

Answer»

`N lt O lt Cl lt AL`
`O lt N lt Al lt Cl`
`Al lt N lt O lt Cl`
`Cl lt N lt O lt Al`

ANSWER :C
Discussion
42.

Which of the following is the major product for the given reaction ?

Answer»

3-bromo-2-methylpentane
2-bromo-2-methylpentane
1-bromo-2-methylpentane
4-bromo-2-methylpentane

Answer :B
Discussion
43.

Which of the following pairs has both members from the same group of the periodic table?

Answer»

Mg-Ba
Mg-Na
Mg-Cu
Mg-Cl

Answer :A
Discussion
44.

What is the trend of formation of ionic compound in alkaline earth metals?

Answer»

INCREASES down the group
Decreases down the group
Decreaes ACROSS the period
Remains same in the PERIODIC table

Answer :A
Discussion
45.

The value of Delta H and DeltaS or a reaction are respectively 30 kJ mol^(-1) and 100 KJ^(-1)mol^(-1). Then the temperature above which the reaction will become spontaneous is

Answer»

300K
30K
100K
`20^(@)C`

SOLUTION :`DeltaG=DeltaH-TDeltaS`
At 300K, `DeltaG=30000Jmol^(-1)-300Kxx100KJ^(-1)mol^(-1)`
`DeltaG=0`
Above 300K: `DeltaG` will be negative and reaction becomes SPONTANEOUS.
Discussion
46.

What is the shape of BF_(3)andNH_(3)

Answer»

Solution :Shape of `BF_(3)` is TRIGONAL planer and `NH_(3)` is PYRAMIDAL.
Discussion
47.

Write the resonating structures for the following molecules. CO_(2)

Answer»

SOLUTION :
Discussion
48.

Which of the following will not show geometrical isomerism?

Answer»




SOLUTION :N//A
Discussion
49.

Which is/are true about nitration of chlorobenzene using conc. NO_(3)//H_(2)SO_(4)

Answer»

Nitration is catalyzed by chloro substitution on the ring.
Attack of `NO_(2)^(+)` occur at ortho/para position of benzene ring
p-nitro chloro benzene is PRODUCT in largest AMOUNT among three ISOMERIC PRODUCTS
PRESENCE of Lewis acid catalyze the reaction.

Solution :Statement B & C are correct..
Discussion
50.

To neutralise completely 20 mL of 0.1M aqueous solution of phosphorus acid (H_3PO_3), the volume of 0.1 M aqueous KOH solution required will be ?

Answer»

10 mL
20 mL
40 mL
60 mL

Solution :`H_(3)PO_(3)` is a dibasic acid and ionises as follows:
`H_(3)PO_(3) 2-)`
KOH is a monoacid base. Hence,
0.1 M KOH = 0.1 N KOH
`0.1 M H_(3)PO_(3) = 0.2 N H_(3)PO_(3)`
`underset(KOH)(N_(1)V_(1)) = underset(H_(3)PO_(3))(N_(2)V_(2))`
`0.1 XX V_(1) = 0.2 xx 20`
or `V_(1) = 40 mL`
Discussion