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.

When we heat an iron bar, it first becomes red, then yellow and finally begins to glow with white light and then blue light. Why ?

Answer»

SOLUTION :The change in colour is due to increase in the frequency of radiation emitted on heating as RED colour LIES in the lower frequency REGION while BLUE colour lies in the high frequency region.
Discussion
2.

When a greater number of electrons from excited hydrogen atoms reach the ground state, then

Answer»

The intensity of SPECTRAL lines in Lyman series increases
The NUMBER of lines in Lyman series increases
Both the intensity and number lines in Lyman series increase.
There is no OBSERVABLE CHANGE in spectrum

Answer :A
Discussion
3.

Which of the following is a linear molecule?

Answer»

`BeCl_2`
`H_2O`
`SO_2`
CH_4`

ANSWER :A
Discussion
4.

Which one of the following processes will produce hard water ?

Answer»

SATURATION of WATER with `CaCO_3`
Saturation of water with `MgCO_3`
Saturation of water with `CaSO_4`
ADDITION of `Na_2SO_4` to water

Answer :C
Discussion
5.

What happens when:

Answer»

magnesium is burnt in air
Quicklime is heated with silica
Chlorine REACTS with slaked LIME
Calcium nitrate is heated

Solution :(i). When magnesium is burnt in air, it gives brilliant flame forming magnesium oxide and magnesium nitride.
`2Mg+O_(2)rarr2MgO`(Magnesium oxide)
`3Mg+N_(2)rarrMg_(3)N_(2)` (Magnesium nitride)
(ii). When quicklime `(CaO)` is heated with silica, it forms calcium SILICATE.
`CaO+SiO_(2)overset(Above 1270 K)(rarr) underset(("Calcium sillicate"))(CaSiO_(3))`
(iii). When chlorine reacts with slaked lime, it forms bleaching powder.
`underset(("Slaked lime"))(Ca(OH)_(2))+Cl_(2)rarrunderset(("Bleaching powder"))(CaOCl_(2)+H_(2)O)`
(iv). When calcium nitrate is heated, it decomposed to give `CaO,NO_(2)` and `O_(2)`.
`2Ca(NO_(3))_(2)overset(rarr)2CaCO+4NO_(2)+O_(2)uarr`
Discussion
6.

What is the hybridisation of carbon in problem

Answer»

SOLUTION :`H_(3) underset(underset(sp^(3))(UARR))(C ) - underset(underset(sp)(uarr))(C ) -= N` (B) `H_(2) underset(underset(sp^(2))(uarr))(C )= underset(underset(sp)(uarr))(C )= underset(underset(sp^(2))(uarr))(CH_(2))` (c ) `H_(3) underset(underset(sp^(3))(uarr))(C )- underset(underset(sp^(3))(uarr))(CH_(3))` (d) `underset(underset(sp^(2))(uarr))(CH_(2)) = underset(underset(sp^(2))(uarr))(CH) - underset(underset(sp^(3))(uarr))(CH_(2)) - underset(underset(sp^(2))(uarr))(C )-= underset(underset(sp)(uarr))(CH)` (E ) `underset(underset(sp^(3))(uarr))(CH_(3))- underset(underset(sp^(2))(uarr))overset(overset(OH)(|))(C )= O`
Discussion
7.

What is the role of a catalyst in a catalysed reaction

Answer»

LOWERS the ACTIVATION energy
Increases the activation energy
Affects the free energy change
Affects the ENTHALPY change

Solution :All SUBSTANCE have average energy and before the reaction occurs energy of the REACTANT should be higher than the average energy. We also know that catalyst lower the activation energy. Therefore, rate of reaction is increased.
Discussion
8.

Which of the following represents redox reaction ?

Answer»

`Cr_(2)O_(7)^(-2) +2OH^(-) rarrCrO_(4)^(2-)+ H_(2)O`
`SO_(5)^(2-) +I^(-)rarrI_(2)+SO_(4)^(2-)`
`Ca(OH)_(2)+Cl_(2) rarrCa(ClO)_(2)+CaCl_(2)`
`PCl_(5) rarrPCl_(3)+Cl_2`

SOLUTION :a) `overset(+6)underset(_)Cr_(2)O_7^(2-)+2OH^(-)RARROVERSET(+6)(CrO_4^(2-))+H_2O`
b) `overset(+8)underset(_)(S)O_5^(2+)+I^(-)rarrI_2^(0)+overset(+6)(S)ulO_4^(2-)`
C) `Ca(OH)_(2)+Cl_(2)^(0) rarr Caoverset(+1)((ClO))_(2)+CaCl_(2)^(-1)`
d) `overset(+5 -1)(PCl_5) rarr overset(+3-1)(PCl_3)+Cl_(2)^(0)`
Discussion
9.

Write the electronic configurations and calculate the bond orders of H_(2)^(+) , H_2 and He_2 Why the bond length in H_(2)^(+) is longer than that in H_2 ?

Answer»

Solution :`{: ("Species""""Electronic configuration"""Nb""Na"""Bond order"),(H_(2)^(+)""(SIGMA1S)^(1)""1""0""0.5),(H_(2)""(sigma1s)^(2)""2""0""1),(He_(2)""(sigma1s)^(2)(sigma**1s)^(2)""2""2""0):}`
Then bond length in `H_(2)^(+)` is longer than in `H_(2)` because in `H_(2)^(+)` only ONE ELECTRON is present to SHIELD the two nuclei from mutual repulsion. In `H_(2)` there are two electrons to hold the two nuclei, thus the nuclear repulsion is less than that in `H_(2)^(+)`. Hence nuclear separation in `H_(2)^(+)` is more thanin `H_(2)`.
Discussion
10.

The volume of 0.1 M NaOH will be required to neutralise 100 ml of 0.1 ml H_(3)PO_(4) using methyl red indicator to change the colour from pink (acidic medium) to yellow (basic medium) is 10^(x). What is x?

Answer»


Solution :Methyl red indicates FIRST step IONISATION of `H_(3)PO_(4)`
`H_(3)PO_(4)iffH^(+)+H_(2)PO_(4)^(-)`
`N_(1)V_(1)=N_(2)V_(2)implies0.1xx1xxV_(1)=0.1xx1xx100`
`V_(1)=100ml=10^(2)ml`
Discussion
11.

Which of the following systems are aromatic?

Answer»





Solution :ALTHOUGH (a) has 10 CONJUGATED pi ELECTRONS it is non-aromatic due to LACK of planarity of the ring as

(b) has 16(4N) pi-electrons, hence antiaromatic. (c) (azulene) and (d) are aromatic system as they satisfy Huckel rule.
Discussion
12.

Which of the following have zero dipole moment?

Answer»

TRANS-2,3-dichloro-2-butene
cis-2,3-dichloro-2-butene:trans-3-hexene
cís-2-pentene

Solution :DIPOLE MOMENTS CANCEL out each other in trans COMPOUNDS
Discussion
13.

What pH do you expect for 10^(-8) M solution of an acid ?

Answer»

SOLUTION : CLOSE to 7 but `LT 7`.
Discussion
14.

When 100 ML of 1.0 M HCl was mixed 100MI of 1.0 M NaOH in an insulated beakertat constant pressure, a temperature incease of 5.7^(0)C was measured for the beaker and its contents (Expt.1) Because th enthalpy of neutralization of a c 5.7^(0)C strong acid with a strong base is constant (-57.0 kJ moL- I), this experiment could be used to measure the calorimeter constant. In a second experiment (Expt.2) , 100 ML of 2.0 M acetic acid (K_(a) =2.0 xx 10^(-5)) was mixed with 100 ML of 1.0 m NaOH (under identicalconditions to Expt. 1) Where a temperaturerise of 5.0^(0)C was measured. (Consider heat capcity of all solution as 4.2 Jg^(-1) and density of all solution as 1.0 gmL^(-1)) Enthalpy of dissociation (in KJ Mol^(-1)) of acetic acid obtained from Expt, 2 is

Answer»

`1.0`
`10.0`
`24.5`
`51.4`

SOLUTION :N//A
Discussion
15.

Which set of reagentswould you use to form the following compound?

Answer»

`HO-CH_(2)-CH_(2)-OH`and`CH_(2)=O`
`OH-CH_(2)-CH=O`and`CH_(2)= O`
`O=CH-CH = O`and `CH_(2) = O`
`O=CH-CH =O ` and`HO-CH_(2)-OH`

ANSWER :1
Discussion
16.

What is the name of the reaction 2CH_(3)CH_(2)SH rarr CH_(3)CH_(2)CH_(2)-S-S-CH_(2)CH_(2)CH_(3) Wheter codensation oxdation reduction or polymerization

Answer»

SOLUTION :This is na exaple of oxidatin reaction since TWO H - ATOMS have been removed
Discussion
17.

When l=0,the number of electrons that can be accommodated in the subshell is…….

Answer»

SOLUTION :If l=0,NUMBER of ELECTORNS=(2l+1)
`=2(2xx0+1)=2`
Discussion
18.

When 100 ML of 1.0 M HCl was mixed 100MI of 1.0 M NaOH in an insulated beakertat constant pressure, a temperature incease of 5.7^(0)C was measured for the beaker and its contents (Expt.1) Because th enthalpy of neutralization of a c 5.7^(0)C strong acid with a strong base is constant (-57.0 kJ moL- I), this experiment could be used to measure the calorimeter constant. In a second experiment (Expt.2) , 100 ML of 2.0 M acetic acid (K_(a) =2.0 xx 10^(-5)) was mixed with 100 ML of 1.0 m NaOH (under identicalconditions to Expt. 1) Where a temperaturerise of 5.0^(0)C was measured. (Consider heat capcity of all solution as 4.2 Jg^(-1) and density of all solution as 1.0 gmL^(-1)) The p^(H) of the solution after Expt.2 is

Answer»

`2.8`
`4.7`
`5.0`
`7.0`

SOLUTION :N//A
Discussion
19.

What is F-centre ?

Answer»

Solution :The site where ELECTRON is ENTRAPPED in THEANION VACANCY is called F-centre.
Discussion
20.

Which of the following is incorrect for ideal solution ?

Answer»

<P>1) `Delta H _(MIX) =0`
2) `Delta V _(mix) =0`
3) `DeltaP = P _("obsetved")-P _("CALCULATED by raoults law") =0`
4) `Delta G _(mix =0`

SOLUTION :For an ideal solution, `Delta S _(mix) ne 0,` Hence `Delta G _(mix) ne 0`
`therefore` Incorrect is `Delta G _(mix )=0`
Discussion
21.

Which of the following have equal concentration-

Answer»

200 ML SOLUTION of 20g NaOH
100 mL solution of 40g NaOH
200 mL solution of 0.5 MOL KCl
200 mL solution of 20g KOH

Answer :A::C
Discussion
22.

Write the stability order of following resonating structures :

Answer»

<P>

ANSWER :`(P)IgtII;""(Q)IIgtI;""(R)IgtII;""(S)IIgtI`
Discussion
23.

Which of the following on treatment with hot concentrated acidified KMnO_(4) will give 2-methylhexane-1,6-dioic acid as the only organic product ?

Answer»




ANSWER :C
Discussion
24.

The volume of nitrogen is measured by which apparatus in Dumas method?

Answer»


ANSWER :NITROMETER
Discussion
25.

Which orbitaldiagram gives an insightto the highest ionization energy ?

Answer»




ANSWER :C
Discussion
26.

The values of K_(p) and K_(p_(2)) for the reaction X hArr Y+Z ...(1) and A hArr 2B...(2) Are in the ratio 9: 1 . It the degree of dissociationof X and A be equal , calculate the ratio of the total prssures of (1) and (2) at equilibrium.

Answer»

Solution :Suppose total pressure at EQUILIBRIUM for reactions (1) and (2) are `P_(1)and P_(2)` respectively . Then
` {:(,X,hArr,Y,+,Z),("Intial.",1"MOLE",,0,,0),("At EQM.",1-alpha,,alpha,alpha,"Total"1+alpha):}`
` P_(X) = (1-alpha)/(1+alpha) P_(1), p_(Y) = alpha/(1+alpha) p_(1),p_(Z) = alpha/(1+alpha)P_(1)`
` K_(p_(1)) = ((apha)/(1+alpha) P_(1))^(2)/((1-alpha)/(1+alpha)P_(1))=(alpha^(2)P_(1))/(1- alpha^(2) )CONG alpha^(2) P_(1) `
`{:(,A,hArr,2B,),("Intial",1"mole",,0,),("At eqm.",1-alpha,,2 alpha,"Total"=1=alpha):}`
` p_(A) = (1-alpha)/(1 +alpha)p^(2),p^(B) = (2alpha)/(1 + alpha) P^(2)`
` K_(p_(2)) = ((2alpha)/(1+alpha)P_(2))^(2)/((1-alpha)/(1+alpha)P^(2))= (4 alpha^(2))/(1-alpha^(2)) P_(2) = 4 alpha ^(2) P_(2) `
` (K_(p_(1)))/(K_(p_(2)))= (alpha^(2) P_(1))/(4alpha^(2)P_(2)) = (P_(1))/(4 P_(2))= 9/1 ("Given") or (P_(1))/(P_(2))= 36 /1 = 36 :1 `
Discussion
27.

When light with a wavelength of 400 nm falls on the surface of sodium , electrons with a kinetic energy of1.05 xx 10^(5) " J mol"^(-1) are emitted . What is the minimum energy needed to remove an electron from sodium ?

Answer»


ANSWER :`a=3.2255 XX 10^(19) J `,
Discussion
28.

When CH_(2)=CH-COOH is reduced with LiAlH_(4), the compound obtained will be :

Answer»

`CH_(3)-CH_(2)-COOH`
`CH_(2)=CH-CH_(2)OH`
`CH_(3)-CH_(2)-CH_(2)OH`
`CH_(3)-CH_(2)-CHO`

Answer :B
Discussion
29.

When light with a wavelength of 400 nm falls on the surface of sodium , electrons with a kinetic energy of1.05 xx 10^(5) " J mol"^(-1) are emitted . What is the maximum wavelength of light that will cause a photoelectron to be emitted ?

Answer»


ANSWER :`b=616 NM`
Discussion
30.

What do you observe in the spectrum of NaCl ?

Answer»

SOLUTION :TWO YELLOW LINE with WAVELENGTHS `5890Å and 5896 Å`
Discussion
31.

What arehorizontal rowsand verticalcolumns of the periodictablecalled ?

Answer»

SOLUTION :Horizontalrows arecalledperiodswhileverticalcolumnsare calledgroups.
Discussion
32.

What is weak electrolyte ? Give examples.

Answer»

Solution :A weak ELECTROLYTE is defined as a substance which dissociates to a SMALL extent in aqueous solution and hence conducts electricity also to a small 1 extent.
e.g. `NH_4OH, OH_3COOH` etc.
In weak electrolytes, as they are partly ionized, an EQUILIBRIUM is set up between the ions and the UNIONIZED electrolyte.
Discussion
33.

Which contains both polar and non-polar bonds ?

Answer»

` NH_(4) CL`
HCN
` H_(2) O_(2)`
`CH_(4)`

Solution :`H - O- O -H, H - O `is POLAR , O- O is NON -polar .
Discussion
34.

Which of the following has least bond enthalpy ?

Answer»

`Pb-Pb`
`Si-Si`
`Ge-Ge`
`Sn-Sn`

ANSWER :A
Discussion
35.

What is the importance of heavy water with regard to nuclear power generation ?

Answer»

SOLUTION :It is used as a moderator in atomic REACTORS to SLOW down the speed of neutrons produced as a result of fission and thus helps to CONTROL the nuclear reactions.
Discussion
36.

What is Fission of a covalent bond? Explain its type with example and main difference

Answer»

Solution :The FISSION of a covalent bond means the REACTION of BREAKING the covalent bond.
The covalent bond can get CLEAVED EITHER by: (i) heterolytic cleavage OR (ii) homolytic cleavage
Discussion
37.

The vapour density of undecomposed N_(2)O_(4) is 46. When heated, vapour density decreases to 24.5 due to is dissociation to NO_(2). The % dissociation of N_(2)O_(4) at the final temperature is

Answer»

80
60
40
70

Solution :`{:(N_(2)O_(4),hArr,2NO_(2)),(1,,0),(1-alpha,,2alpha):}`
`:. (VD_("innitial"))/(VD_("FINAL")) = (n_("final"))/(n_("innitial"))`
`(46)/(25.4) = (25.4)/(46) = (1+alpha)/(1)`
`1.8 = 1+alpha` `implies alpha = 0.8`or`80%`
Discussion
38.

When N_(2) goes to N_(2)^(+), then N-N bond distance ……….and when O_(2) goes to O_(2)^(+) the O-O bod distance…….

Answer»

INCREASES, DECREASES
decreases, increases
increases, increases
decreases, decreases

ANSWER :C
Discussion
39.

Which of the following compounds cannot exhibit mesomeric effect

Answer»

`CH_(3)-CH_(2)=CH-overset(oplus)(C)H-CH_(3)`

`CH_(2)=CH-CH_(2)-bar(N)H_(2)`
`CH_(3)-O-CH_(2)-CH_(3)`

Answer :C::D
Discussion
40.

Which of the following compounds will not form an anhydride ?

Answer»

Propandioic ACID
Succine acid
Hexandioic acid
cis-But-2-en-1, 4-dioic acid

Solution :Propandioic acid will not form an anhydride as it does not form FIVE or six membered ring
`HOOC - CH_(2) - COOH underset(-2H_(2)O)rarr underset("CARBON suboxide")(O = C = C = C = O)`
Discussion
41.

What is the melting point of benzene if Delta H_("fusion") = 9.95 kJ//mol and Delta S_("fusion") = 35.7 J//K- mol?

Answer»

`278.7^(@)C`
278.7K
300K
298K

Solution :`DELTA S = (Delta H)/(MP) rArr 35.7 = (9.95 XX 1000)/(MP)`
`rArr` MP = 278.7 K
Discussion
42.

What type of addition reactions do alkenes usually undergo ?

Answer»

SOLUTION :ELECTROPHILIC
Discussion
43.

Thermodynamically most stable allotrope of carbon is

Answer»

DIAMOND
GRAPHITE
Coal
Coke

SOLUTION :Graphite is more STABLE than Diamond
Discussion
44.

X, Y and Z elements have 4, 5 and 7 valence electrons . Draw the structure of XH_(4), YH_(5) YH_(3)" and " H - Z.

Answer»

SOLUTION :
Discussion
45.

Write redox couples involved in the reaction (a) to (d) given in que. No. 34. Cu+Zn^(+2)toCu^(+2)+Zn Mg+Fe^(+2)toMg^(+2)+Fe Br_(2)+2Cl^(-)toCl_(2)+2Br^(-) Fe+Cd^(+2)toCd+Fe^(+2)

Answer»

SOLUTION :(a) `Cu^(+2)//CuandZn^(+2)//Zn`
(B) `MG^(+2)//MgandFe^(+2)//Fe`
( c) `Br_(2)//Br^(-)andCl_(2)//CL^(-)`
`Fe^(+2)//FeandCd^(+2)//CD`
Discussion
46.

When KMnO_4 acts as an oxidizing agent and ultimately forms MnO_(4)^(2-), MnO_2, Mn_2O_3 and Mn^(2+). The number of electrons transferred in each case respectively is

Answer»

1,3,4,5
1,5,3,7
4,3,1,5
3,5,7,1

Answer :A
Discussion
47.

What is the characteristic of resonance structure?

Answer»

Solution :(i) The POSITION of ATOMIC CENTRE is same.
(ii) Total electron REMAIN same. (iii) `pi` or p electron migrate and change their position
Discussion
48.

When CaC_2 is heated in atmospheric nitrogen in an electric furnace the compound formed is

Answer»

`CA(CN)_(2)`
`CaNCN`
`CaC_(2)N_(2)`
`CaNC_(2)`

Solution :`CaC_(2)+N_(2)overset(I ATM)tounderset("Nitrolium (or)")underset("calcium CYANAMIDE")(CaNCN)`
Discussion
49.

Vingegar contains

Answer»

`10 - 20%` ACETIC ACID
10% acetic acid
`7 - 8%` acetic acid
100% acetic acid

Solution :`7 - 8%` acetic acid
Discussion
50.

X' is most inert element and 'Y' is most reactive element in the long form of the periodic table. 'X' and 'Y' are respectively

Answer»

H, F.
He, F
He, Cs
Xe,F

Answer :B
Discussion