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 is lanthanide contraction? Give one of its consequences.

Answer»


Answer :The DECREASE in the size of ATOMS with INCREASE in atomic number of LANTHANIDES is called LANTHANIDE contraction'. The properties of lanthanides become close to each other
Discussion
2.

Which one of the following statements is wrong for gases

Answer»

GASES do not have a definite shape and VOLUME
Volume of the gas is equal to the volume of the container confirming the gas
Confined gas exerts uniform pressure on the walls of its container in all directions
MASS of the gas cannot be determined by weighting a container in which it is enclosed

Solution :The mass of gas can be determined by weighing the container , filled with gas and again weighting this container after removing the gas . The difference between the two weights GIVES the mass of the gas .
Discussion
3.

The weight of H_2O_2present in 80 ml 10V H_2O_2solution is

Answer»

3.2 G
4.2 g
2.4 g
3.6 g

Answer :C
Discussion
4.

What is the pH of acidic buffer ? How it is formed ?

Answer»

Solution :The pH of acidic buffer is LESS than 7. It is PREPARED by EQUAL MIXTURE of WEAK acid and its salt with strong base.
`CH_3COOH+CH_3COONa` pH:4.75
Discussion
5.

Write the IUPAC names of the following compounds.

Answer»

Solution :(i) 2-Phenylethanol, (ii) 1, 1, 1-Trichloro-2, 2-diphenylethane
(iii) 2-Phenylethanamine, (iv) 2- (CHLOROMETHYL) chlorobenzene
(v) 3, 3-Diphenylbutan-2-ol, (VI) 1, 2-bis (4-chlorophenyl) ETHANE
(vii) 2, 4-Dinitrobenzenamine, (VIII) 4-Nitroso-N-dimethylbenzenamine
(ix) Benzene 1, 4-dicarboxylic acid, (x) 1-Phenylpropanone.
Discussion
6.

Vander Waal's equation for one mole of CO_(2)gas at low pressure will be

Answer»

<P>`(P + a/(V^2))V = RT`
`P(V- B) = RT - a/(V^2)`
`P = (RT)/(V - b)`
`P ((RT)/(V - b)- a/(V^2))`

ANSWER :A
Discussion
7.

Which of the following are stored under oil?

Answer»

ALKALI METALS
Coinage metals
NOBLE metals
Phosphorous

Answer :A
Discussion
8.

Which of the following alcohols on oxidation gives a carboxylic acid with lesser number of carbon atoms ?

Answer»

`CH_(3)CH_(2)CH_(2)CHO`
`CH_(3)CH_(2)CH_(2)OH`
`(CH_(3))_(3)C.OH`
`(CH_(3))_(3)C-CH_(2)-OH`

Solution :Secondary and tertiary alcohols on oxidation give CARBOXYLIC ACIDS having lesser number of carbons.
Discussion
9.

Which represents an example of Friedel-Crafts reaction

Answer»

`C_6 H_6 + C_2 H_5 CL OVERSET(AlCl_3 ) to C_6H_5 C_2 H_5 + HCl`
`C_2H_5 OH + HCl overset(ZnCl_2)to C_2H_2Cl + H_2O`
`C_6H_5 Cl + CH_3COCl overset(AlCl_3)to C_6H_5COCH_3+Cl`
`C_2H_5Br+ MG overset("Either")to C_2H_5Mg Br`

SOLUTION :Formation of alkyl benzene from benzene in presence of `AlCl_3`
Discussion
10.

Which of the following statements about hydrogen is incorrect ?

Answer»

Solution :Hydrogen has three ISOTOPES of which TRITIUM is radioactive and RATE. Dihydrogen ACTS as reducing agent.
Discussion
11.

Water add in 1.0 mL 0.1 M HCl solution to give 50 mL. Calculate pH change of solution.

Answer»

Solution :Initially PH =1 , After dilution pH=2.7 , The change in pH = 1.7 increases.
Discussion
12.

Which of the following is the most powerful oxidising agent?

Answer»

`F_(2)`
`O_(2)`
`Br_(2)`
`I_(2)`

SOLUTION :Acidified `K_(2)Cr_(2)O_(7)` solution oxidises `SO_(2)" into "Cr_(2)(SO_(4))_(3)`.
`3S overset(+4)(O_(2))+K_(2)Cr_(2)O_(7)+H_(2)SO_(4) to K_(2)SO_(4) +Cr_(2) (overset(+6)(SO)_(4))_(3)+H_(2)O`
Hence, oxidation state of SULPHUR changes from +4 to +6.
Discussion
13.

Which of the following compounds is oxidised to prepare ethyl methyl ketone ?

Answer»

2-Propanol
1-Butanol
2-Butanol
t-Butyl alcohol

Solution :`underset("2-Butanol")(CH_(3)CH_(2)-underset(OH)underset(|)overset(H)overset(|)(C)-CH_(3)) overset([O])RARR underset("Methyl ethyl ketone")(CH_(3)CH_(2)-overset(O)overset(||)(C)-CH_(3))`
Discussion
14.

Which of the correct IUPAC names of the following compound ? H_3C-CH_2-CH_2-overset(HC(CH_3)_2)overset|"CH"-undersetunderset(H_3C-CH-CH_2CH_3)|"CH"-CH_2-CH_2-CH_2-CH_2-CH_3

Answer»

5-Butyl-4-isopropyldecane
5-Ethyl-4-propyldecane
5-sec-Butyl-4-isopropyldecane
4-(1-methylethyl)-5-(1-methylpropyl) decane

Solution :ALTHOUGH IUPAC NAME for sec-butyl and isopropyl groups are 1-methylpropyl and 1-methylethyl respectively yet both these NAMES also RECOMMENDED for IUPAC nomenclature .
Discussion
15.

Which of the following is true about chemisorption?

Answer»

It is reversible in nature
It is usually occurs at low temperature
It is highly specific in nature
The attractive forces between adsorbate and adsorbent are van der WAAL's forces.

Solution :CHEMISORPTION occurs through formation of CHEMICAL bond and hence it is specific in nature.
Discussion
16.

The volume strength of 1.54 N H_(2)O_(2) solution is:

Answer»

4.8L
5.2L
8.4L
8.8L

SOLUTION :(c ) STRENGTH of solution =`NXX"Equivalent MASS of" H_(2)O_(2)`
`=(1.5"equiv" L^(-1))xx(17"equiv"^(-1))`
`underset(68g)(2H_(2)O_(2)) to underset(22.4L)(2H_(2)O+O_(2))`
68g of `H_(2)O_(2)` evolve `O_(2)` under N.T.P conditions=22.4L
25.5g of `H_(2)O_(2)` evolve `O_(2)` under N.T.P conditions `=((22.4L)xx(25.5g))/(68g)=8.4L`
Discussion
17.

Which of the following statements in not correct regarding preparation of NaOH/

Answer»

NAOH is prepared by ELECTROLYSIS of sodium chloride in castner-kellner cell.
sodium metal DISCHARGED at cathode cmbines with mercury to form sodium amalgam,.
Chlorine is evolved at anode.
Amalgam is heated to separate Na and Hg.

Solution :Amalgam is TREATED with water to give sodium hydroxide and hydrogen gas. ltbr. 2Na-amalgam`+2H_(2)Oto2NaOH+2Hg+H_(2)`
Discussion
18.

Which of trhe following statements is not correct?

Answer»

The first inoisation energies (in ` KJ "mol"^(-1)`) of carbon, silicon , GERMANIUM , tin, and lead are 1086, 786,761,708 and 715 respectively:Down the GROUP , electronegativity dereases from B to T1 in boron FAMILY.
Among oxides of the elements of carbon family CO is NEUTRAL , GeO is acidic and SnO is amphoteric.
The 4f and 5f INNER transition elements are placed seperately at the bottom of the periodic table to maintain its struction.

Answer :A::C::D
Discussion
19.

When FeS_2is oxidized with sufficient O_2then its oxidation product is found to be Fe_(2)O_3 and SO_2 if the molecular weight of FeS_(2), Fe_(2) O_3 and SO_2are M. Ma and Mc, then which of the following statements are correct?

Answer»

EQUIVALENT wt. of `FeS_2`is M/11
the molar RATIO of `FeS_2`to `O_2`is 4:11
the molar ratio of `FeS_2` to `O_2`is 11:4
The molar ratio of `Fe_(2)O and SO_2`is 1:4

SOLUTION :`4 FeS_(2)+11O_(2) rarr2Fe_(2)O_3+8SO_2`
Discussion
20.

The vapour density of a gas is 11.2. Calculate the volume occupied by 11.2 g of the gas at NTP. [Hint: mol. Wt =2 xx V.D]

Answer»


ANSWER :11.2 LITRES
Discussion
21.

Write the coordination number of each ion in the following crystals : (i)NaCl (ii)CsCl (iii)ZnS (iv)Na_2O

Answer»

Solution :(i)`Na^+`=6,`Cl^-`=6 , (II)`Cs^+`=8, `Cl^-`=8 , (III)`ZN^(2+)`=4 , `S^(2-)` =4 , (iv)`CA^(2+)`=8 , `F^-` =4 , (v)`Na^+` =4 , `O^(2-)`= 8
Discussion
22.

Which of the following is used in high temperature thermometry ?

Answer»

Na
Ga
Tl
Hg

Solution :Ga exists as liquid from `30^@ C ` UPTO `2000^@C` and hene it is USED in HIGH TEMPERATURE thermometry
Discussion
23.

Which of the following statement is wrong for lyophobic sol

Answer»

Dispersed PHASE is generally in organic material
Can be EASILY coagulated by small addition of electrolyte
Dispersed phase particles are poorly hydrated and colloid is stabilised DUE to charge on thhe colloidal particle
Reversible in nature that is after COAGULATION can be easily set into colloidal form

Answer :D
Discussion
24.

When an electron with charge .e. and mass .m. moves with velocity .v. around the nucleus having nuclear charge .Z. in a circular orbit of radius .r., the potential energy of electron is

Answer»

`(ZE^(2))/(R)`
`(Ze^(2))/(r^2)`
`(-Ze^2)/(r)`
`(mv^2)/(r)`

SOLUTION :PE = `-(Ze^2)/(r)`
Discussion
25.

The van der Waal equation of gas is (P+ (n^(2)a)/(V^(2))) (V - nb) = nRT

Answer»

(i) `CO_(2)` , (ii) `H_(2)`
(i) `CH_(4)` , (ii) `CO_(2)`
(i) `H_(2)` , (ii) `CO_(2)`
`O_(2)`, (ii) `H_(2)`

Solution :(i)Order of intermolecular attraction is `CO_(2)gt CH_(4)gt O_(2)gt H_(2)`
In `CO_(2)`, intermolecular FORCES increases with number of electrons in a molecule.
(ii)Size increases in order of `H_(2)LT O_(2)CH_(4)lt CO_(2)` Hence, `H_(2)` will have lowest VALUE of B.
Discussion
26.

Which of the following is an example of heterogeneous equilibrium ?

Answer»

Synthesis of HI
DISSOCIATION of `PCl_(5)`
`Acid HYDROLYSIS of ester
Decomposition of limestone

Solution :`CaCO_(3) (s) to Ca O(s) + CO_(2) (g)`
Here `CO_(2)` is in gaseous state while `CaCO_3` and CaO are in solid state .
Discussion
27.

Which of the following species is reduced by N_(2)O_(2) ?

Answer»

`[Fe(CN)_(6)]^(4-)`
`[Fe(CN)_(6)]^(3-)` in alkaline SOLUTION
`NO_(2)^(-)`
`I^(-)//HCl`.

Solution :`|Fe(CN)_(6)|^(3-)` is reduced to `|Fe(CN)_(6)|^(4-)` in alkaline solution.
`2|Fe(CN)_(6)|^(3-)+2OH^(-)+H_(2)O_(2)to|Fe(CN)_(6)|^(4-)+2H_(2)O_(2)+O_(2)`.
Discussion
28.

Which is the pH of 10^(-8) M HCl from 8.0, 7.0, 6.95 ? Why ?

Answer»

SOLUTION :6.95 because the solution is ACIDIC THEREFORE the VALUE of pH is less than 7.0.
Discussion
29.

The total charge in coulombs required to complete the electrolysis is :

Answer»

24125
48250
`96500`
`193000`

Solution :`NA^(+) + e^(-) rarr Na`
MOLES of Na discharged at CATHODE = 1 mol
Total charge needed to COMPLETE the electrolysis is
`= 2 xx F =xx 96500 C`
`= 193000 C`.
Discussion
30.

Two oxides of a non-metal X contain 50% and 40% of non -metal respectively. If the formula of the first oxide is XO_2, then the formula of second oxide is

Answer»


ANSWER :`M_(2)O_(3)`
Discussion
31.

What is the exothermic reaction?

Answer»


Answer :Reaction TAKES PLACE with the liberation of HEAT.
Discussion
32.

Which of the following oxides is amphoteric ?

Answer»

`SnO_(2)`
`CaO`
`SiO_(2)`
`CO_(2)`

Solution :`SnO_(2)` IC amphoteric,`SiO_(2)` and `CO_(2)`are acidicwhile `CaO` isbasic.
Discussion
33.

Write only arrangement of electron and its shape of the following. HgCl_(2) " (ii) " BF_(3) "(iii) " NH_(4)^(+) " (iv) PCl_(5) (v) SF_(6) "(vi) " SO_(2)" (vii)" NH_(3) "(viii)" H_(2) O "(ix)"SF_(4) " (x)" CIF_(3) " (xi)" BrF_(5) " (xii)" XeF_(4)

Answer»

SOLUTION :Use table Q. No: 52 & 53
Discussion
34.

What aresuper heavy element?

Answer»

Solution :ELEMENTWITH `Z GT 100` which havehighdensitiesare called super heavy element.
Discussion
35.

The state of hybridisation of S in SO_(2) in similar to that of C in

Answer»

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

Answer :B
Discussion
36.

When is treated with nitrating mixture (HNO_(3)+H_(2)SO_(4)), we get :

Answer»




ANSWER :a
Discussion
37.

What is SI units of viscosity coefficient (eta) ?

Answer»

Pascal
Ns `m^(-2)`
`KM^(-2)`s
N `m^(-2)`

Solution :The SI unit of viscosity coefficient `(eta)` is N `m^(2)` s or N s `m^(-2)` PAGE 5/63).
Discussion
38.

Which of the following cannot be produced by acidic dehydration of alcohols?

Answer»

Ethers
ALDEHYDE
Alkyl HYDROGEN sulphate
Alkene

Solution :Aldehyde is OBTAINED by oxidation or dehydrogenation of `1^(@)` of alcohols.
Discussion
39.

Which of the following is most reactive towards sulphonation?

Answer»

<P>m - XYLENE
o- Xylene
TOLUENE
p -Xylene

SOLUTION : m Xylene
Discussion
40.

Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?

Answer»

SOLUTION :Due to its smallest SIZE`Li^(+)` can polarize WATER molecules easily than the other alkali METAL IONS.
Discussion
41.

Write the resonating structures for the following molecules. CO_(3)^(2-)

Answer»

SOLUTION :
Discussion
42.

When a 20 mL of 0.08 M weak base BOH is titrated with 0.08 HCl , the pH of the solution at the end point is 5. What will be the pOH if 10 mL 0.04 M NaOH is added to the resulting solution?[Given:log 2= 0.30 and log 3 = 0. 48 )

Answer»

<P>` 5.40`
` 5.88`
` 4.92`
None of these

Solution :At end point
` N_1V_1 = N_2V_2 , [BCl ]= (20 XX 0.08)/( 20+20 ) =0.04`
` 5= (1)/(2) [14 -P^(K_b) -log 4 xx 10^(-2) ]rArr P^(K_b) =5.4 `
` {:(B^(+) +, OH^(-)to, BOH) ,( 1.6 m " mol " , 0.4 m " moles " ,0),(1.2 m " mol " ,-, 0.4 m " mole" ):}`
` P^(OH) =5.4 +log ""(1.2)/(0.4)=5.88`
Discussion
43.

Which of the following is free radical addition reaction ?

Answer»


`CH_2=CH_2+HBr to CH_3-CH_2-Br`
`CH_3-CH=CH_2+HBr OVERSET(R_2O_2)to CH_3-CH_2-CH_2-Br`
`CH_3-CH=CH_2+HCl to CH_3-undersetunderset(CL)(|)CH-CH_3`

ANSWER :C
Discussion
44.

What happens when ferrimagnetic Fe_(3)O_(4) is heated to 850 K and why ?

Answer»

Solution :Ferrimagnetic `Fe_(3)O_(4)`on heating to 850 K becomes paramagnetic. This is due to GREATER alignment of domains (spins) in one direction on heating .
Discussion
45.

What is the difference between total kinetic energy and translational kinetic energy ? For what type of molecules, the two are equal ?

Answer»

Solution :Total KINETIC energy is the sum of translational, vibrational and rotational kinetic ENERGIES. The total kinetic energy is equal to the translational kinetic energy for MONOATOMIC gases (He, Ne etc) as they do not POSSES vibrational and rotational motion but have only translational motion.
Discussion
46.

Which of the following salts solution will act as a buffer ?

Answer»

`NH_(4)CH_(3)COO(aq.)`
`NH_(4)CI(aq.)`
`NaCH_(3)COO(aq.)`
`NaCI(aq.)`

Solution :It acts as a buffer because its cation `(NH_(4)^(+))` REACTS with `OH^(-)` from added base to form a weak base `(NH_(3)) :NH_(4)^(+)+OH^(-)rarr NH_(3)+H_(2)O`
Its NEGATIVE ion `(CH_(3)COO^(-))` reacts with `H^(+)` from added acid to from a weak acid `(CH_(3)COOH) :CH_(3)COO^(-)+H^(+)rarr CH_(3)COOH`
Discussion
47.

What will be the molarity of 200 ml solution of sulphuric acid having pH = 1 ?

Answer»

0.5 M
0.1 M
0.05 M
1 M

ANSWER :C
Discussion
48.

Which of the following is true about I and II?

Answer»

I is ECLIPSED, II is staggered
II is eclipsed, I is staggered
both are eclipsed
both are staggered

Answer :B
Discussion
49.

The solubilty product of the electrolyte of the type A_2B_3 is (s is the solubility in mol/ lit)

Answer»

`108 s^(5) `
`72 s^(5)`
` 108 s^(2)`
` 10S ^(2) `

Solution :`A_2B _3 hArr 2 underset( 2s) A +3 underset( s) B , KsP =(2s) ^(2) (3S) ^(3)=108 s^(5) `
Discussion
50.

Which of the foilowing pairs of substances on reaction will not envolve H_(2) gas?

Answer»

Iron and `H_(2)SO_(4)(aq)`
Iron and steam
Copper and HCL(aq)
SODIUM and ethanol.

Solution :(C ) Copper and HCl (aq) do not REACT
Discussion