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.

Which one of the following is used as an insecticide and as a soil sterilising agent?

Answer»

CHLOROFORM
CHLORAL
CHLOROPICRIN
TETRACHLOROMETHANE

SOLUTION :Chloropicrin
Discussion
2.

Thermodynamics is not concerned about ..............

Answer»

ENERGY changes involved in a CHEMICAL REACTION.
the extent to which a chemical reaction proceeds.
the rate at which a reaction proceeds.
the FEASIBILITY of a chemical reaction.

Solution :Thermodynamics is not CONCERNED with rate at which a reaction proceeds.
Discussion
3.

What is the mass percent of oxygen in ethanol ?

Answer»

0.5214
0.1313
0.16
0.3473

Solution :Molecularformula of ETHENOL `=C_2H_5OH`
MOLAR mass of ethenol of `2xx12.01+6xx1.008+16`
=46.068g
Mass percent of OXYGEN `=(16)/(46.068)xx100=34.73%`
Discussion
4.

What are Fullurenes? How are they propared?

Answer»

SOLUTION :Carbon exhibits many allotropicforms, both crystallins as well as amorphous.
Diamond and graphite are two well known crystalline forms of carbon, third form of corbon known as fullerences.
Fullerences are makde by heating of graphite in an electric are in the presence of inert gases such as helium or argon. The sooty material formed by condensation of vapourised `C^(a)` small molecular consists of mainly C60 with smaller quantity of C70 and traces of fallerence CONSISTING of EVEN number of carbon atoms upto 350 or above.
Discussion
5.

Which of the following alkali metal shows high melting point ?

Answer»

LI
Al
SR
CS

Solution :DUE to the smallest size of Li.
Discussion
6.

Which of the following has larger dipole moment ? Explain. 1-Butyne or 1-Butene

Answer»

Solution :The DIRECTION of dipole moments of individual bonds in 1-butyne and 1-butene are shown below :

The resultant dipole moment of both 1-butyne and 1-butene is due to the dipole moment of `CH_3CH_2C` and C-H bonds which oppose each other . Since a SP CARBON is more electronegative than a `sp^2` carbon, therefore, the dipole moment of `CH_3CH_2(sp^3)`-C(sp) bond in 1-butyne is more than that of `CH_3CH_2(sp^3)-C(sp^2)` bond in 1-butene. As a result, the dipole moment of 1-butyne is more than that of 1-butene.
Discussion
7.

Which one of the following is isoelectronic with Ne?

Answer»

`N^(3-)`
`MG^(2+)`
`AL^(3+)`
All the above

Answer :D
Discussion
8.

What is Delta U for the process described by figure. Heat supplied during the process q= 100kJ

Answer»

`+50kJ`
`-50kJ`
`-150kJ`
`+150kJ`

SOLUTION :`DELTA U = q + W`
W = area under graph`= (1)/(2) xx 1 xx (1 +2) = (3)/(20 xx 10^(5)N - m^(2)`
`Delta U = +100 - (3)/(2) xx (10^(5))/(1000) = 100-150= -50J`
Discussion
9.

Type of hybridization in graphite

Answer»

SP
`sp^2`
`sp^3`
`dsp^2`

ANSWER :B
Discussion
10.

Which of the following does not result in an increase in the entropy ?

Answer»

CRYSTALLISATION of SUCROSE from solution
Rusting of Iron
Conversion of ICE to water
Vapourisation of camphor

Answer :A
Discussion
11.

The units of constant b used in van der Waals' equation are ………….. .

Answer»

SOLUTION :`L MOL^(-1)`
Discussion
12.

Which is a non-aromatic compound ?

Answer»




Solution :CYCLOOCTATETRAENE has 8 `pi`-electrons. It does not follow Huckel's rule and is also not planar (has tub SHAPED structure ), therefore , it is non-aromatic.
Discussion
13.

Which of the following statement is wrong-

Answer»

nitrogen cannot form `dpi-p PI` bond
single N-N bond is weaker than the single P-P bond
`N_(2)O_(4)` has two resonance structures
The stability of HYBRIDES INCREASES from `NH_(3)` to `BiH_(3)`due to increase in size of the central ATOM

Solution :The stability of hybrides of group-15 decreases from `NH_(3)` to `BiH_(3)` due to increase in size of the central atom.
Discussion
14.

What will be the temperature when the rms velocity is four times of that at 300 K ?

Answer»

300 K
900 K
4800 K
1200 K

Solution :(C ) `U_(rms)("velocity")=sqrt((3RT)/(M))`
HENCE, `upropsqrttrArr(u_(1))/(u_(2))=sqrt((T_(1))/(T_(2)))` From Eq. (i), `(1)/(4)=sqrt((300)/(T_(2)))`
`(1)/(16)=(300)/(T_(2))`
`T^(2)=16xx300`
4800 K
Discussion
15.

Write Lewis representation of following molecules / Ions. (i) H_(2)(ii) O_(2) (iv) NF_(3) (iv) CO_(3)^(2-) (vi) HNO_(3)

Answer»

SOLUTION :LEWIS REPRESENTATION of molecule/ions are SHOWN in FOLLOWING table :
Discussion
16.

Which of the following is ferromagnetic?

Answer»

CALCIUM METAL
Iron metal
SODIUM metal
ZINC metal

Answer :B
Discussion
17.

Which of the following species is an electrophile ?

Answer»

`H_2O`
`NH_3`
`R-O-H`
`CO_2`

SOLUTION :Electrophiles are ELECTRON DEFICIENT. They are Lewis ACIDS
Discussion
18.

Threshold frequency, v_(0) is the minimum frequency which a photon must possess to eject an electron from a metal. It is different for different metals. When a photon of frequency 1.0 xx 10^(15) s^(-1) was allowed to hit a metal surface, an electron having 1.988 xx 10^(-19)J of kinetic energy was emitted. Calculate the threshold frequency of this metal. Show that an electron will not be emitted if a photon with a wavelength equal to 600 nm hits the metal surface.

Answer»

Solution :We KNOW thathv =`hv_(0)+ke` or
`hv-ke =hv_(0)=-1.988xx10^(-19)`
`hv_(0)=6.626 xx10^(-19)-1.988xx10^(-19)j`
`hv_(0)=4.638xx10^(-19)j`
`v_(0)=(4.638 xx10j)/(6.626xx10^(-34)=0.699xx10^(15)s^(-1)`
when `lambda=600 nm =600 xx10^(-19) m`
thus `v lt v_(0)`hence no electro will beemitted
Discussion
19.

Which of the following expression is correct for a CsCl unit cell with lattice parameter,a?

Answer»

`r_(cs+)+r_(cl^(-))=2a`
`r_(cs+)+r_(cl^(-))=(a)/(sqrt2)`
`r_(cs+)+r_(cl^(-))=(SQRT3)/(2)a`
`r_(cs+)+r_(cl^(-))=(3)/(2)a`

Solution :(c ) CSCL crystal has bcc STRUCTURE,
` Rightarrow r_(Cs)+r_(Cl^(-))+(sqrt3)/(2)a`
Discussion
20.

Thiosulphate reacts differently with iodine and bromine in the reactions given below 2S_(2)O_(3)^(2-) +I_(2)rarrS_(4)O_(6)^(2-)+2I^(-) S_(2)O_(3)^(2-)+2Br_(2)+5H_(2)O rarr 2SO_(4)^(2-) +2Br^(-) +10H^(+) Which of the following statements in correct ?

Answer»

a.Bromine is a STRONGER oxidant than iodine
b. Bromine is a weaker oxidant than iodine
c. Thiosulphate UNDERGOES oxidation by bromine and reduction by iodine in these reactions
d. Bromine undergoes oxidation and iodine undergoes reduction in these reactions

SOLUTION :`Br_2`is STRONG oxidant than`I_2`
Discussion
21.

Which of the following properties of atom could be explained correctly by Thomson Model of atom

Answer»

Overall neutrality of ATOM.
Spectra of hydrogen atom.
Position of electrons, protons and neutrons in atom.
Stability of atom.

Solution :J.J. Thomson, in 1898, given plum pudding, (raisin pudding or watermelon) model of atom.An IMPORTANT feature of model is that the MASS of the atom is assum ED to be uniformly distributed over the atom. This model is EXPLAIN the overall neutrality of the atom.
Discussion
22.

When copper is treated with a certain concentration of nitric acid, nitric oxide and nitrogen dioxide are liberated in equal volumes according to the following equation xCu + yHNO_(3)rarr Cu(NO_3)_2 + NO + NO_2 + H_(2)O . The coefficient of x is ______

Answer»


Solution :Balanced EQUATIONS for producing NO and `NO_2`respectively are :
`3Cu+8HNO_3Cu(NO_3)_(2)+2NO+4H_(2)O...(i)`
`Cu+4HNO_(3) rarr Cu(NO_3)_(2)+2NO_(2)+2H_(2)O....(ii)`
Here NO and `NO_2`are EVOLVED in equal volumes, therefore , adding Eqns. (i) and (ii) , have
`4Cu + 12 HNO_3 rarr 4Cu(NO_3)_(2) +2NO_2 +2NO + 6H_(2)O " or " 2Cu+6HNO_3 rarr 2Cu(NO_3)_(2) +NO_2 +NO+3H_2O`
Thus coefficients X and y of `Cu and HNO_3`respectively are 2 and 6.
Discussion
23.

Which of the following reactions does not take place

Answer»




All the above

Solution :NITRO benzene does not COMBINE with alkyl halide as `NO_2` is DEACTIVATING group. Benzene does not combine with alkenes or aryl compounds in the presence of `AlCl_3`, as it PREFERS electrophilic SUBSTITUTION.
Discussion
24.

Which of the following reactions shows reduction of water ?

Answer»

`2H_(2)O + 2Na to 2NAOH + H_(2)`
`6CO_(2) + 12H_(2)O to C_(6)H_(12)O_(6) + 6H_(2)O + 6O_(2)`
`2F_(2) + 2H_(2)O to 4H^(+) + 4F^(-) + O_(2)`
`P_(4)O_(10) + 6H_(2)O to 4H_(3)PO_(4)`

SOLUTION :Water is reduced to dihydrogen by highly ELECTROPOSITIVE metals. In this reaction `H_(2)O` is reduced to `H_(2)`. In other two reactions, `H_(2)O` is oxidised to `O_(2)` and `P_(4)O_(10)` is hydrolysed by water.
Discussion
25.

Write structures of different chain isomers of alkanes corresponding to the molecular formula C_(6)H_(14). Also write their IUPAC names.

Answer»

Solution :Hexane `(C_(6)H_(14))` has 5 ISOMERS which are as FOLLOWS :
Discussion
26.

To find formula of a compound composed of iron and carbon monoxide Fe_(x)(CO)_(y),the compound is burned in pure oxygen and following reaction occurs: Fe_(x)(CO)_(Y) + O_(2) rightarrow Fe_(2)O_(3) + CO_(2) If 19.6gm of Fe_(x)(CO)_(y) is burnt and 8gm Fe_(2)O_(3) is formed, then empirical formula of Fe_(x)(CO)_(y) is:

Answer»

`Fe_(2)(CO)_(5)`
`FE(CO)_(4)`
`Fe(CO)_(3)`
`Fe(CO)_(5)`

Answer :D
Discussion
27.

Which is manufactured by electrolysis of fused sodium chloride?

Answer»

`NAOH `
`NACIO `
`NaClO_3`
`NA`.

SOLUTION :`Na`.
Discussion
28.

Two gases A and B having the same volume diffuse through a porous partition in 20 and 10 seconds respectively. The molecular mass of A is 49u. Molecular mass of B will be

Answer»

50.00u
12.25u
6.50u
25.00u

Answer :B
Discussion
29.

What happens when warm aqueous Barium hydroxide solution is electrolysed?

Answer»


ANSWER :`H_2` GAS is PRODUCED
Discussion
30.

What are the harmful effects of photochemical smog and how can they be controlled ?

Answer»

Solution :The COMMON components of photochemical smog are ozone, nitric OXIDE, acrolein, formaldehyde and peroxyacetyl nitrate (PAN).
Photochemical smog causes serious health problems. Both ozone and PAN act as powerful EYE irritants.
Ozone and nitric oxide irritate the nose and throat and their high concentration causes headache, chest pain, dryness of the throat, cough and difficulty in breathing.
Photochemical smog leads to cracking of RUBBER and extensive damage to plant life. It also causes corrosion of metals, stones, BUILDING materials, rubber and painted surfaces.
Discussion
31.

Which of the following is the formula of 3-methyl pent3-ene-2-ol

Answer»




ANSWER :B
Discussion
32.

which ofthe following represents correct order of conductivity in solids

Answer»

` k_("metals")gtgt k_("insulators") lt k_("semiconductors")`
`k_("metals")ltlt k_("insulator") lt k_("semiocductors")`
`k_("metals") K_("semiconductors") GT k_("insulators")= "ZERO"`
`k_("metals") lt k_("semiconductors") gt K_("insulators") NE "Zero"`

Answer :C::D
Discussion
33.

Which one of the following equation is not correct ?

Answer»

`DELTA G^(@) = - RTlnK`
`DELTAG^(@) = DeltaH^(@) - T Delta S`
`-RT lnK = Delta H^(@) - T Delta S^(@)`
`ln K = (Delta H^(@))/(T) - (Delta S^(@))/(R)`

Solution :ln `k = (Delta H^(@))/(T) - (Delta S^(@))/(R)`
Discussion
34.

What is the relationship between the members of following pairs of structure ? Are they structural or geometrical isomers or resonance contributors? (c ) H- overset(overset(""^(+)OH)(||))(C )-OH " " H - overset(overset(OH)(|))(C^(+))- OHs

Answer»

SOLUTION :(a) They are structural ISOMERS: `C_(5)H_(10)O`
`CH_(3)-CH_(2)- OVERSET(overset(O)(||))(C )-CH_(2)CH_(3) and CH_(3)-CH_(2)-CH_(2)- overset(overset(O)(||))(C )-CH_(3)`
In fact they are position isomer and metameres
(b) They are trans and cis isomer and metameres
(c ) They are RESONANCE structure because position of centre of atom are constant and the position of electrons are differ.
Discussion
35.

What is the distance between two layers of carbon atom in graphite ?

Answer»

`1.42A^@`
`1.35A^@`
`3.4A^@`
`3.42A^@`

ANSWER :C
Discussion
36.

Which of the following compound have O-O bonding ?

Answer»

`H_2S_2O_6`
`H_2S_2O_8`
`H_2S_2O_3`
`H_2S_4O_6`

ANSWER :B
Discussion
37.

What type of glass is obtained when borax is added that ?

Answer»

Solution :PYREX GLASS it is a glass which is HEAT resistant . And can WITHSTAND a very high TEMPERATURE.
Discussion
38.

Which of the following has maximum bond cell ?

Answer»

`H_(2) O`
`NH_(3)`
`CO_(2)`
`CH_(4)`

SOLUTION :`CO_(2)`
Discussion
39.

Which scientist has obtained benzene first ?

Answer»

Kekule
Friedel-Craft
Michal Ferade
August Hoffman

Answer :C
Discussion
40.

Which of the following is not formed when glycerol reacts with HI ?

Answer»

`CH_(2)=CH-CH_(2)I`
`CH_(2)OH-CHI-CH_(2)OH`
`CH_(3)-CH=CH_(2)`
`CH_(3)-CHI-CH_(3)`

Solution :`CH_(2)-OH-CHI-CH_(2)OH` is not formed in the REACTION of glycerol with HI.
Discussion
41.

Which one of the following is used as a bleach?

Answer»

 `Cl_(2)` water <BR>`Br_(2)` water
Water gas
Liquid hydrogen

Answer :a
Discussion
42.

Which of the followingsets of quantumnumberis notpossible ?

Answer»

1 and 3
2,3 and 4
1,2,3 and 4
2,4 and 5

ANSWER :D
Discussion
43.

The reason for small radius of Ga compared toAl is "……………….".

Answer»

POOR screening EFFECT of d and F orbitals
increases in nuclear charge
presence of higher orbitals
higher atomic number

Solution :Poor shielding of d-electronand increase in nuclearcharge. Thus, options (a) and (b) correct.
Discussion
44.

What will be the concentration of iodine in solution?

Answer»

`1.1M`
`0.011M`
`0.0011M`
`0.11M`

SOLUTION :MOLARITY `(M)=(n_(I_2))/(V_L)`
`n_(I_2)=(Mass_(I_2))/(Molar mass_(I_2))=(0.070g)/(254g mol^(-1))`
`V_L=250 mLxx(IL)/(1000mL)`
`:. M=(0.070g)/(254 g mol^(-1)xx250mL)xx((1000mL)/(1L))`
`=0.0011 mol L^(-1)`
Discussion
45.

Which of the following has the highest nucleophilicity?

Answer»

`F^(-)`
`OH^(-)`
`CH_(3)^(-)`
`NH_(2)^(-)`

Answer :C
Discussion
46.

Write the names of isotopes of hydrogen what is the mass ratio of these isotopes ?

Answer»

Solution :Hydrogen has three isotopes: protium, `(._1^1H)`, Deuterium, (`._1^2H` or D) and tritium, (`._1^3H` or T).
These isotopes differ from one another in respect of the presence of NEUTRONS.
Ordinary hydrogen, protium, has no neutrons, deuterium (also known as heavy hydrogen) has one and tritium has two neutrons in the nucleus.
In the year 1934, an American scientist, Harold C. Urey, got Nobel Prize for SEPARATING hydrogen isotope of mass number 2 by physical methods.
The predominant form is protium. TERRESTRIAL hydrogen contains 0.0156% of deuterium mostly in the form of HD. The tritium concentration is about one atom per `10^18` atoms of protium. Of these isotopes, only tritium is radioactive and emits low energy B- particles. Its half life period is (`t_(1/2)`=12.33 years)
Since the isotopes have the same electronic configuration, they have almost the same chemical properties.
The only difference is in their RATES of reactions, mainly due to their different enthalpy of bond DISSOCIATION.
However, in physical properties these isotopes differ considerably due to their large mass differences.
Discussion
47.

Which of the following is not true?

Answer»

Camphor
Benzoic acid
Naphthalene
Nitrobenzene

Answer :D
Discussion
48.

What happens if a liquid is heated to the critical temperature of its vapours ?

Answer»

Solution :The meinscus between the LIQUID and the VAPOUR disappears (SURFACE tension of the liquid becomes ZERO).
Discussion
49.

Whichelectronic configurationof an element hasabnormally highdifferencebetweensecondand thirdionizationenthalpy ?

Answer»

`1s^(2), 2s^(2)2p^(6) , 3S^(1)`
`1s^(2) , 2s^(2) 2p^(6) ,3s^(2) 3p^(1)`
`1s^(2) , 2s^(2) 2p^(6) , 3s^(2) 3p^(2)`
`1s^(2) , 2s^(2) 2p^(6) , 3s^(2)`

SOLUTION :Sinceelement (d) hastwo s- electrons in THETHE valenceshelltherefore its `Delta _(i) H_(3)`is muchhighest than its `Delta_(i) H_(2)` sincethe third electronhas tobe lost from the inertgasconfiguration,
Discussion
50.

Three lines are drawn from a single corner of an FCC unit cell to meet the other corner such that they are found to pass through exactly only 1 octahedrat void, no voids of any type and exactly 2 tetrahedral voids with 1 octahedral voids. Identify the line ?

Answer»

EDGE length
Body diagonal
FACE diagonal
A LINE which PASSES through only TWO face centres of opposite faces

Solution :
Discussion