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.

The best reagent for converting 2-phenylpropanamide into 2-phenylpropanamine is_____.

Answer»

excess `H_(2)`
`Br_(2)` in aqueous NaOH
iodine in the presence of RED phosphorus
`LiAlH_(4)` in ether

Solution :`UNDERSET("2-Phenylpropanamide")(C_(6)H_(5)-OVERSET(CH_(3))overset(|)(C)H-CONH_(2) overset(LiAlH_(4)//Ether)to underset("2-Phenylpropanamine")(C_(6)H_(5)-overset(CH_(3))overset(|)(C)H-CH_(2)NH_(2))`
Discussion
2.

The best reagent for converting, 2-phenylpropanamide into 1-phenylethanamine is

Answer»

excess `H_2//Pt`
`NaOH//Br_2`
`NaBH_4 //`methanol
`LiAlH_4 //`ether

Solution :`UNDERSET(" 2-Phenylpropanamide")(C_6 H_5 - OVERSET(CH_3) overset(|) (CH )-CONH_2) underset("(Hofmann bromamide REACTION)") overset(Br_2//NaOH)to underset("1-Phenylethanamine ")(C_6 H_5 - overset(CH_3 ) overset(| )(CH ) -NH_2)`
Discussion
3.

The best reagent for converting, 2-phenylpropanamide into 1-phenylethanemine is….

Answer»

EXCESS `H_2//Pt`
`NaOH//Br_2`
`NaBH_4 //`METHANOL
`LiAlH_4 //`ether

Solution :`underset(" 2-Phenylpropanamide")(C_6 H_5 - OVERSET(CH_3) overset(|) (CH )-CONH_2) underset("(HOFMANN bromamide reaction)") overset(Br_2//NaOH)to underset("1-Phenylethanamine ")(C_6 H_5 - overset(CH_3 ) overset(| )(CH ) -NH_2)`
Discussion
4.

The best reagent for converting 2-phenylpropanamide into 2 phenylpropanamine is:

Answer»

excess `H_(2)//Pt`
`NaOH//Br_(2)`
`NaBH_(4)//"METHANOL"`
`LiAlH_(4)//"ETHER"`

SOLUTION :`underset("2 - Phenylpropanamide")underset(CH_(3))(C_(6)H_(5)CH-CONH_(2))overset(Br_(2),KOH)rarrunderset("1 - Phenylethanamine")underset(CH_(3))(C_(6)H_(5)CH-NH_(2))`
Discussion
5.

The best oxidising agent for oxidation of CH_(3)-CH=CH-CHO" to "CH_(3)-CH=CH-COOH is

Answer»

Baeyer's REAGENT
Tollens' reagent
SCHIFF's reagent
acidified DICHROMATE.

Solution :Tollens' reagent oxidises only -CHO to -COOH group.
Discussion
6.

The best reagent for converting, 2-phenyl-propanamide into 1-phenylethanamine is________

Answer»

EXCESS `H_(2)//PT`
`NaOH//Br_(2)`
`NaBH_(4)//`methanol
`LiAlH_(4)//`Ether

Solution :`C_(6)H_(5)-overset(CH_(3))overset(|)(C)H-CONH_(2) underset(("Hofmann bromamide reaction"))overset(Br_(2)//NaOH)to underset("1-Phenylethanamine")(C_(6)H_(5)-overset(CH_(3))overset(|)(C)H-NH_(2))`
Discussion
7.

The best oxidant & non metal with the highest SRP value

Answer»

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

Solution :AMONG halogens `F_(2)` is BEST oxidant.
Discussion
8.

The bestmethylatingagentis

Answer»

`CH_(3)Cl`<BR>`CH_(3)Br`
`CH_(3)F`
`CH_(3)I`

Solution :`CH_(3) -I`is bestmethylatingagentbecauseof C-Ibond lengthis morethanthatofC-Cl , C-Br , C-Fbondlength.
Discussion
9.

The best methof for the separetion of naphthalene and benzoic acid from their mixture is,

Answer»

distillation
sublimation
chromatography
crystallisation

Solution :Among the given compounds naphthelene is volatile but benzoic acid is non-volatile (it forms a dinner). So, the BEST method for their SEPARATION is sublimation, which is APPLICABLE to compounds which can be converted directly into the vapour phase from its SOLID state on heating and back to the solid state on cooling. HENCE it is the most appropriate method.
Discussion
10.

Thebestmethoudfor thepreparationof 2,2 -dimehtylbutane is viathe reactionof :

Answer»

`e_(3)VBr and MeVH_(2) BR` inNa/ ether
`(Me_(3)C)_(2)CULI and MeCH_(2)Br`
`(MeCH_(2))_(2)CULi andMe_(3)CBR`
`Me_(3)CMgl andMeCH_(2)I`

Answer :B
Discussion
11.

The bestmethods to reducecyclohex-2- en -1- one to cyclohex -2-en - 1- oneis /are

Answer»

`PC C, CH_(2) Cl_(2)`
MPV REDUCTION
`NaBH_(4)`
`Ni//H_(2)`

Answer :A::B
Discussion
12.

The best method to purify impure acetone is

Answer»

`CH_(3)COCH_(3)+HCl to CH_(3) -overset(OH)overset(|)underset(Cl)underset(|)C-CH_(3) overset("heat")to CH_(3)COCH_(3)`
`CH_(3)COCH_(3)+NaHSO_(3) to CH_(3)-overset(OH)overset(|)underset(CH_(3))underset(|)C-SO_(3)Na overset(Na_(2)CO_(3))to CH_(3)COCH_(3)`
`CH_(3)COCH_(3)+HCNto CH_(3)-overset(OH)overset(|)underset(CN)underset(|)C-CH_(3) overset(HOH)toCH_(3)COCH_(3)`
`CH_(3)COCH_(3)+H_(2)SO_(4) to CH_(3)-overset(OH)overset(|)underset("OSO"_(3)H)underset(|)C-CH_(3) to overset("heat")to CH_(3)COCH_(3)`

ANSWER :B
Discussion
13.

The best method to prepare neopentyl chloride is

Answer»

`(CH_(3))_(3)C CH_(2)OH overset(PCl_(5),Delta)rarr`
`(CH_(3))_(3)C CH_(2)OH overset(HCl, Delta) rarr`
`(CH_(3))_(3)C CH_(2)OHoverset(SOCl_(2), "PYRIDINE")rarr`
`(CH_(3))_(3) C CH_(3) overset(Cl_(2) h upsilon, Delta)rarr`

Solution :
On the other HAND, free radicals do not undergo rearrangement and hence the best method of preparation is through free RADICAL chlorination.
`underset(""CH_(3))underset("|")overset(""CH_(3))overset("|")(CH_(3)-C-CH_(3))overset(Cl_(2),h upsilon)rarr underset(CH_(3))underset("|")overset(CH_(3)"")overset("|")(CH_(3)-C-CH_(2)Cl)`
Discussion
14.

The best method to prepare neopentyl chloride is (CH_(3))_(3)C-CH_(2)-OHoverset(PCl_(5)//Delta)to ( B) (CH_(3))_(3)C-CH_(2)-OHoverset(HCl//Delta)to © (CH_(3))_(3)C-CH_(2)-OHoverset(SOCl_(2)//"Pyridine")to (D) (CH_(3))_(3)C CH_(3)overset(Cl_(2)//hv)underset(Delta)to

Answer»

Solution :
On the other hand, free radicals do not undergo REARRANGEMENT. HENCE, the BEST method of preparation is throough free radical CHLORINATION.
Discussion
15.

The best method to prepare fluoroethane is

Answer»

`C_(2)H_(5)OH overset(HF//H_(2)SO_(4))rarr`
`C_(2)H_(5)OH overset(HF//SbF_(5))rarr`
`C_(2)H_(5)Cl overset(Hg_(2) F_(2)//Delta)rarr`
`C_(2)H_(6) overset(F_(2)//h upsilon) rarr`

SOLUTION :Fluoro derivatives of alkanes can be obtained by halogen exchange method using inorganic fluorides such as `SbF_(3), AGF, Hg_(2)F_(2)` , etc.
`2C_(2)H_(5)Cl+Hg_(2)F_(2) rarr 2C_(2)H_(5)F+Hg_(2)Cl_(2)`
Discussion
16.

The best method to prepare cyclohexene from cyclohexanol is by using

Answer»

CONC. `HCl+ZnCl_(2)`
Conc. `H_(3)PO_(4)`
HBr
Conc. HCl

Answer :B
Discussion
17.

The best method to prepare 3-methylbutan-1-ol from 3-methylbut-1-ene is

Answer»

addition of `H_(2)O` in presence of dil. `H_(2)SO_(4)`
addition of HCI followed by hydrolysis with `NaOH_("(aq)")`
oxymercuration-demercuration
hydroboration-oxidation reaction.

Solution :`underset("3-methylbut-1-ene")(CH_(3)-underset(CH_(3))underset(|)CH-CH=CH_(2)) underset((ii) H_(2)O_(2)//OH^(-))overset((i) B_(2)H_(6)//THF)to underset("3-methylbutane-1-ol")(CH_(3)-underset(CH_(3))underset(|)CH-CH_(2)-CH_(2)OH)`
This conversion requires anti-Markovnikov.s addition of `H_(2)O` and hence is possible only via hydroboration oxidation.
Discussion
18.

The best method to prepare cuclohexane from cyclohexanol is by using :

Answer»

CONC. HCl + `ZnCl_(2)`
conc. `H_(3)PO_(4)`
HBr
conc.HCl

Solution :N//A
Discussion
19.

The best method of prepared fluoroethane is

Answer»

`C_2H_5OH OVERSET(HF//H_2SO_4. DELTA)(to)`
`C_2H_5OH overset(HF//SbF_5. Delta)(to)`
`C_2H_5OH overset(Hg_2F_2. Delta)(to)`
`C_2H_6overset(F_2.hv)(to)`

Solution :PREPARATION of Alkyl FLUORIDE (D).
Discussion
20.

The best method for the separation of naphthalene and benzoic acid from their mixture is :

Answer»


ANSWER :C
Discussion
21.

The best method for the separation of naphthalene and benzoic acid formtheir mixture is

Answer»

Chromatography
Crystallisation
Distillatoin
Sublimation

Solution :MIXTUREOF benzoic ACID and naphthalene can be SEPARATED from HOT WATER in which benzoic acid dissolves but naphthalene does not.
Discussion
22.

The best method for the preparation of primary amines is

Answer»

`R-X overset(NH_(3))toR-NH_(2)`
`R-X overset((i)NaN_(3))underset((II)LiAiH_(4))toR-NH_(2)`
`R-X overset(NH_(3))underset(Al_(2)O_(3)//Delta)toR-NH_(2)`
`R-X overset(NaNH_(2))toR-NH_(2)`

Solution :`R-X overset(NH_(3))underset(Al_(2)O_(3)//Delta)toR-NH_(2)`
Discussion
23.

The best method for the conversion of an alcohol into an alkyl chloride is by treating the alcohol with

Answer»

`PCl_(5)`
`SOCl_(2)` in presence of pyridine
Dry HCl in the presence of anhydrous `ZnCl_(2)`
`PCl_(3)`

Solution :`R-OH+SOCl_(2) UNDERSET("Reflux")overset("Pyridine")(to)R-Cl+SO_(2)uarr+HCluarr`
This is the best method for preparing alkyl chloride from alcohols. The advantage of this method over USING phosphorus chlorides is that the byproducts of the above reaction i.e. `SO_(2)` and HCl are gases which can EASILY escape from the reaction MIXTURE.
Discussion
24.

The best method for preparation of Me_(3)CCN is

Answer»

To react `Me_(3)COH` with `HCN`
To react `Me_(3)CBR` with NaCn
To react `Me_(3)CMgBr` with CICN
To react `Me_(3)CLI` with `NH_(2)CN`

Solution :It's a `S_(N)^(2)` reaction where `Me_(3)C-MgBr+Cl-CNrarrMe_(3)C-CN+Mg(Cl)Br`
Discussion
25.

The best method for preparation of Me_(3)C-CN is:

Answer»

`"to REACT" Me_(3)C to OH "with" HCN`
`"to react" Me_(3)C to Br "with" NaCN`
`"to react" Me_(3)C to MgBr "with" CICN`
`"to react" Me_(3)C to Li"with"NH_(2)CN`

Answer :C
Discussion
26.

The best method for preparation of Me_(3)"CC"Nis

Answer»

to REACT `Me_(3)COH` with HCN
to REAT `Me_(3)CBr` with NaCN
to react `Me_(3)CM_(g)Br` with CICN
to react `Me_(3)Cli` with `NH^(2)` CN

Solution :It is a `S_(N)2` reaction .
`Me_(3)C-MgBr+CI-CN rarrMe_(3)C-CN+Mg(CI)Br`
Discussion
27.

The best indicator for detection of end point in titration of a weak acid and a strong base is NB Figures in the brackets show the pH range of the indicator .

Answer»

METHYL ORANGE (3 to 4)
methyl RED (4 to 6)
bromothylmol BLUE ( 6 to 7.5)
phenolphthalein ( 8 to 9.6)

Answer :d
Discussion
28.

The best indicator for detection of end point in titration of a weak acid and a strong base is

Answer»

Methyl orange (3 to 4)
Methyl red (5 to 6)
Bromothymol blue (6 to 7.5)
Phenolphthalein (8 to 9.6)

Solution :The pH of the solution at the EQUIVALENCE point will be GREATER than 7 due to salt hydrolysis. So an indicator giving colour on the basic SIDE will be suitable.
Discussion
29.

The best Grignard's reagent is ,

Answer»

`CH_(3)Mgl`
`CH_(3)MGCL`
`CH_(3)MGBR`
`CH_(3)MgF`

ANSWER :A
Discussion
30.

The best explanation for the solubility of MnSin dil. HCl is that

Answer»

Solubility PRODUCT of `MnCl_(2)` is less than that of MnS
CONCENTRATION of `Mn^(2+)` is LOWERED by the formation of complex ions with CHLORIDE ions
Concentration of sulphide ions is lowered by oxidation to free sulphur
Concentration of sulphide ions is lowered by formation of the weak acid `H_(2)S`

SOLUTION :It is a characteristic property of IV group, concentration of sulphide ions is lowered by formation of the weak acid `H_(2)S` .
Discussion
31.

The best examples of covalent crystals are ……….. and ………..

Answer»

SOLUTION :DIAMOND, `SiO_(2)`
Discussion
32.

The best electrolyte for the extraction of magnesium metal is

Answer»

`MgCl_2`
`MGO`
`Mg_3 N_2`
`MGS`

ANSWER :A
Discussion
33.

The best electrolyte for coagulation of As_(2) S_(3) sol is

Answer»

NACL
`CuSO_(4)`
`AL(NO_3)_3`
`Th(SO_4)_2`

Solution :`Th^(4+)` ions though have maximum CHARGE but solubitlity of `Th(SO_4)_2` is very less. Hence, `Al(NO_3)` is the best electrolyte.
Discussion
34.

The best conductor of electricity is a 1.0 M solution of

Answer»

Boric ACID
ACETIC acid
Sulphuric acid
Phosphoric acid

SOLUTION :`H_(2)SO_(4) HARR H^(+) + HSO_(4)^(-) hArr H^(+) + SO_(4)^(--)`
Because of it completely ionised.
Discussion
35.

The best conductor of electricity is

Answer»

1M `CH_(3)COOH` solution
1M `H_(2)SO_(4)` solution
1M HCl solution
1M `H_(3)BO_(3)` solution

Answer :B
Discussion
36.

The best conductor of electricity is 1 M solution of :

Answer»

`CH_3COOH`
`H_2SO_4`
`H_3PO_4`
BORIC acid

Answer :B
Discussion
37.

The best colligative property to determine the molecular masses of polymers is ………………… .

Answer»

SOLUTION :OSMOTIC PRESSURE
Discussion
38.

The best combination for the preparation of ether Williamson.s synthesis are

Answer»

`(CH_(3))_(3)CBR`and `CH_(3)ONa`
`(CH_(3))_(3)CBr` and `CH_(3)OH`
`CH_(3)Br` and `(CH_(3))_(3)CONA`
`CH_(3)Br` and `(CH_(3))_(3)COH`

Answer :C
Discussion
39.

The best catayst used to reduce an alkyne to alkene is :

Answer»

MOLYBDENUM oxide
Raney nickel
Lindlar's CATALYST
Zinc dust

Answer :C
Discussion
40.

The best absorbent for ammonia is:

Answer»

WATER
`H_2SO_4`
NaO
NaOH

Answer :B
Discussion
41.

The behaviour of sulphur while reacting with water and alkali is similar to that of

Answer»

CO
`O_(2)`
`O_(3)`
`CO_(2)`

Solution :With lime WATER it behaves similar to `CO_(2)`. First it turns lime water milky due to formation of insdusle `CaSO_(3)`. Which disappears on passing excess of `SO_(2)` due to the conversion of insdusle `CaSO_(3)` to insdusle `Ca(HSO_(3))_(2)`
Discussion
42.

The behavior of Be salt in pure water is

Answer»

Basic
ACIDIC
AMPHOTERIC
Sometimes basic and sometimes acidic DEPENDING UPON its concentration.

Solution :Amphoteric.
Discussion
43.

The bateriostatic antibiotic among the following is

Answer»

Erythromycin
Aminoglycoside
Ofloxacin
Penicillin

Solution :Anitbiotics have either cidal (killing) effect or STATIC (INHIBITORY) effect on MICROBES. Erythromycin is a BACTERIOSTATIC anitbiotic.
Discussion
44.

The battery used in pacemakers is _______.

Answer»

LEAD STORAGE battery
Daniel cell
Leclanche cell
Mercury BUTTON battery

Answer :D
Discussion
45.

The basis fo Al as a reducing agent in thermite process is

Answer»

High exothermic HYDRATION of `AL^(3+)`
High Eox. Pot. Of Al
High exothermic enthalpy of FORMATION of `Al_(2)O_(3)`.
High I.E. of Al

ANSWER :C
Discussion
46.

The basis of kohlraush's law is __________.

Answer»

molar CONDUCTANCE at infinite DILUTION of a WEAK electrolyte
limitating molar conductance
SPECIFIC conductance
limiting specific conductance

Answer :B
Discussion
47.

The basicity order of I, II and IIIis

Answer»

IIIgtIgtII
IgtIIgtIII
IIIgtIIgtI
IIgtIIIgtI

SOLUTION :III GT I gt II
Discussion
48.

The basicity of pyrophosphorous acid (H_(4)P_(2)O_(5)) is ……………… .

Answer»

4
2
3
5

Answer :B
Discussion
49.

The basicityof pyrophosphorous acid(H_(4)P_(2)O_(5)) is

Answer»

4
2
3
5

Answer :B
Discussion
50.

The order of basicity of hydroxides of alkali metals is

Answer»

`LigtNagtRbgtCs`
`NagtLigtRbgtCs`
`CsgtRbgtNagtLi`
`RbgtCsgtNagtLi`

ANSWER :C
Discussion