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.

An alkane is most likely to react with

Answer»

An electrophile
An ALKALI
A nucleophile
A FREE radical

Answer :A
2.

An alkene is most likely to react with:

Answer»

a FREE RADICAL
an alkali
an electrophile
a nucleophile

Answer :A
3.

An alkane has a C/H-ratio (by mass) of 5.1428. Its molecular formula is

Answer»

`C_(5)H_(12)`
`C_(6)H_(14)`
`C_(8)H_(18)`
`C_(7)H_(10)`

Solution :The ratio of C/H in an alkane is 5.1428.
Alkanes have General formula `C_(n)H_(2n+2)`
The MASS ratio of `(C)/(H)` is `(12n)/(2n+2)` or `(6n)/(n+1)`
`(6n)/(n+1) = 5.1428`
`6n = 5.1428n + 5.1428 rarr 0.8572n = 5.1428`
`n = (5.1428)/(0.8572) = 6`
Molecular formula `= C_(6)H_(2n+2) = C_(6)H_(14)`.
4.

An alkane forms isomers if the number of least carbon atom is

Answer»

1
2
3
4

Solution :`UNDERSET("n-butane")(CH_(3)-CH_(2)-CH_(2)-CH_(3))` and `{:(CH_(3)-CH-CH_(3)),("|"),(""underset("Iso-butan")(CH_(3))):}`
5.

An alkane forms isomers if the number of carbon atoms is:

Answer»

GE 1
ge 2
ge 3
ge 4

Answer :D
6.

An alkane ,C_(7)H_(16) , is produced by thereaction oflitthium di-(3 -pentyl ) cuprate with ethyl bromide ,. Whatis thestructure of akane ?

Answer»

Solution : Thisis a corey-Hpouse SYNTHESIS
`[(CH_(3)CH_(2))CH_(2)]CuLi+CH_(3)CH_(2)Brto UNDERSET("3- Ethylpentane")((CH_(3)CH_(3))_(3)CH]`
7.

An alkane C_(6)H_(14) gives onlt twomonochloroalkanes on chlorination. What is the structure of the original alkane ?

Answer»


SOLUTION :`UNDERSET("2,3-Dimethyl BUTANE")(CH_(3)-underset(CH_(3))underset(|)(CH)-underset(CH_(3))underset(|)(CH)-CH)`
8.

An alkane, A on ozonolysis gives two products propanal and propanone. Which of the given statements is incorrect for A?

Answer»

COMPOUND A is pent-2-ene
Compound A on hydrogenation gives 2-methyl pentane
Compound A can UNDERGO bromination reaction
Compound a FORMS 2-bromo, 2-methylpentane on treating with HBr

Answer :A
9.

An alkane (A), C_5H_15, on chlorination at 300^@C gives a mixture of four different monochloro derivatives (B), (c ) , (D) and (E). Two of these derivatives give the same stable alkene (F) on dehydrohlogeantion. On oxidation with hot alkaline KMnO_4 followed by acidification, (F) gives two products (G) and (H). Give structures of (A) to (H) with proper reasoning.

Answer»

Solution :As ALKANE (A), `C_5H_12`, on chlorination gives four monochloroproduct and THUS (A) is ISOPENTANE.
10.

An alkaloidcontains 17.28% of nitrogen and its molecular mass is 162. The number of nitrogen atoms present in on molecule of alkaloid is

Answer»

five
four
three
two

Solution :Amount of nitrogen PRESENT in one MOLE of akaloid i.e., in 162 g `= (162xx17.28)/(100)`
`:.` No. of nitrogen atoms per molecule
`=(162xx17.28)/(100x24)=2`(APPROX.)
11.

An alkaloid contains 17-28% of nitrogen and itsmolecular mass is 162. The number of nitrogen atoms present in one molecule of alkaloid is :

Answer»

five
four
three
two

Solution :Amount of N PRESENT in 1 MOL of alkaloid
` = (162 XX 17.28)/(100)`
no. of N atoms present in 1molecule
` = (162 xx 17.28)/(100 xx 14) = 2 ` APPROX
12.

An alkaline solution of ......... and citrate ions is called ..........

Answer»

SILVER nitrate , Fehling's solution
CUPRIC SULPHATE , SCHIFF's REAGENTS
Silver chloride , Tollen's reagent
Cupric Sulphate , Benedict's solutions

Answer :D
13.

An alkaline metal oxide which is soluble in NaOH has

Answer»

`NACL` STRUCTURE
wurzite structure
`CSCL` structure
rutile structure

Answer :B
14.

An alkalie is titrated against an acid with methyl orange as indicator, which of the following is a correct combination

Answer»

`{:("Base","Acid","End point"),("Strong","Strong","Pinkish red to yellow"):}`
`{:("Base","Acid","End point"),("Weak","Strong","Yellow to pinkish red"):}`
`{:("Base","Acid","End point"),("Strong","Strong","Pink to colourless"):}`
`{:("Base","Acid","End point"),("Weak","Strong","Colourless to pink"):}`

Solution :`UNDERSET("weak base")(NH_(4)OH)+underset("Strong acid")(HCl) to NH_(4)Cl+H_(2)O`
At end point pH will be LESS than 7
as strong acid weak base salt have `pH=7-((pK_(b)+logc))/(2)`
`therefore`Methyl ORANGE will change colour from yellow to pinkish red at the end point.
15.

An alkali salt of palmitic acid is known as :

Answer»

An alkoxide
An ester
A soap
An epoxide

Answer :C
16.

An alkali metal hydride (NaH) reacts with diborane in .A. to give a tetrahedralcompound .B. which is extensively used as reducing agent in organic synthesis. The compounds. The compound .A. and .B. respectively are

Answer»

`(C_2H_5)_2O and NaBH_4`
`C_6H_6 and NaBH_4`
`CH_3COCH_3 and B_3N_3H_6`
`C_2H_6 and C_3H_5Na`

SOLUTION :`2NaH + B_2H_6 UNDERSET(.A.)OVERSET((C_2H_5)_2O)to 22NaBH_4`
Sodium Bromohydride .B..
17.

An alkali metal crystallises in bcc lattice. What is the radius of an atom of the metal ?

Answer»

SOLUTION :`1.86 A^(@)`
18.

An alkali is titrated against an acid with methyl orange as indicator. Which of the following is a correct combination-

Answer»

Base-WEAK, Acid-Strong, End point- Colourless to pink
Base-Strong, Acid-Strong, End point-Pinkish RED to yellow
Base-Weak , Acid-Strong, End point-Yellow to pinkish red
Base-Strong, Acid-Strong, End point-Pink to colourless

Solution :The pH range for the colour CHANGE of methyl orange is 3.9-4.5. In the titration of weak base vs strong acid. the pH of the end point is less than 7. Thus for this KIND of titration. m ethyl orange is the suitable indicator.
19.

An aliphatic nitrocompoundturnred withthe addition of conc. NaOH , followedby additionof excess HNO_(2). Thecolour disapperwith theadditionof excessacidbutreapear if thesolutionis made alkaline. The aliphaticnitrocompoundis .

Answer»

`CH_(3) -CH_(2) - NO_(2)`
`CH_(3) - UNDERSET(NO_(2))underset(|)(CH)-CH_(3)`
`CH_(3) - underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-NO_(2)`
`CH_(3) - underset(NO_(2))underset(|)(CH)-C_(2) H_(5)`

Answer :A
20.

An aliphaticprimaryaminereactswith HNO_(2)in coldto form

Answer»

a nitrile
an ALCHOHOL
a DIAZONIUM
a secondry AMINE

ANSWER :B
21.

An aliphatic hydroxy acid is :

Answer»

Malonic acid
Salicylic acid
Maleic acid
Succinic acid.

Answer :C
22.

An aliphatic amine (X) contains C (61.01%), H (15.25%) and N (23.74%). (X), on treatment with HNO_(2), gave an alcohol (Y) having C(60%) and H(13.33%). (Y), on careful oxidation gave (Z) of vapour density 29. (Z) gave iodoform test. Assign structural formulae to (X), (Y) and (Z).

Answer»

SOLUTION :
23.

An aliphatic compound (A) with a molecular formula C_3H_6O reacts with phenylhydrazine to give compound (B). Reaction of (A) with I_2 in alkaline solution on warming gives a yellow precipitate (C). Identify the compounds A, B and C.

Answer»

Solution :Identification of COMPOUNDS A, B and C is done as under :
`underset("Acetone")(CH_(3)-overset(O)overset(||)C-CH_(3) + C_(6)H_(5)NHNH_(2)) to CH_(3) -underset(CH_(3))underset(|)C= N NHC_(6)H_(5) + H_(2)O`
`CH_(3) -underset(A)overset(O)overset(||)C -CH_(3) + 3I_(2)+ 4NaOH to underset("Iodoform")(CHI_(3)) + CH_(3)COONa + 3NaI + 3H_(2)O`
24.

An aliphatic amine on treatment with alcoholic carbon disulphide and mercuric chloride forms ethyl isothiocyanate, the reaction is known as

Answer»

HOFFMANN's Reaction
Hoffmann's Rearrangement
Hoffmann's mustard oil reaction
Hoffmann's Bromamide degradation reaction.

Solution :`underset((1^(@)" amine"))(C_(2)H_(5)-NH_(2))+S=C=S ("alc.") rarr C_(2)H_(5)-NH-overset(S)overset("||")(C)-SH overset(HgCl_(2))(rarr) HgS+2HCl+underset(("ethylisothiocyanate"),("(SMELL similar to mustard oil)"))(C_(2)H_(5)-N=C=S)`
25.

An aldose is converted into its next higher homologue by :

Answer»

Ruff.s METHOD
Amadori REARRANGEMENT
Kiliani SYNTHESIS
NONE

ANSWER :C
26.

An aldehyde which undergoes Cannizzaro's reaction and reduces Schiff's reagent but does not reduce Fehling's solution is :

Answer»

CH_3CHO
HCHO
`C_6H_5CHO`
Salicylaldehyde

Answer :C
27.

An aldohexose (e.g., glucose) and 2 - oxohexose (e.g., fructose) can be distinguished with the help of

Answer»

TOLLEN's reagent<BR>Fehling's SOLUTION
Benedict solution
`Br_(2)+H_(2)O`

Answer :D
28.

An aldehyde reacts with KCN to form cyanohydrin. In this reaction

Answer»

`CN^-` ACTS as NUCLEOPHILE and does nucleophilic ADDITION
`CN^-` acts as nucleophile and does ELECTROPHILIC addition
`CN^-` acts as an electrophilic and does electrophilic addition
`CN^-` acts as nuclcophile and does nucleophile substitution

Answer :A
29.

An aldehyde on treatment with Zn/HCl yields:

Answer»

`1^@` ALCOHOL
`2^@` alcohol
`3^@` alcohol
None

Answer :A
30.

An aldehyde on treatment with Zn/HCl yields

Answer»

`2^@ ` alcohol
`3^@ C` alcohol
`1^@ ` alcohols
None of the above

Answer :C
31.

An aldehyde on oxidation gives

Answer»

an alcohol
an ACID
an ETHER
a KETONE

ANSWER :B
32.

An aldehyde on oxidation gives :

Answer»

An alcohol
A ketone
An ACID
An AMINE

ANSWER :C
33.

An aldehyde is obtained when an alcohol is :

Answer»

Oxidised
Reduced
Dehydrated
Hydrogenated

Answer :A
34.

An aldehyde can undergo the aldol condensationhaving

Answer»

an AROMATIC ring
no alpha H ATOM
ATLEAST one `alpha`-H atom
at LEAST one `beta`-H atom

Answer :C
35.

An aldehyde group can be present

Answer»

in between carbon chain
at any POSITION in carbon ATOM
only at the end of carbon chain
at the SECOND carbon atom of the carbon chain

Answer :C
36.

An aldehyde can be distinguished from a ketone by the use of the reagent:

Answer»

GRIGNARD's reagent
Schiff's reagent
Hydroxylamine
Hydrazine

Answer :B
37.

An alcoholic solution of dimethylglyoxime is added to an aqueous solution of nickel(II) chloride.Slow addition of ammonium hydroxide led to the precipitation of a bright-red coloured metal complex. Find out the number of hydrogen bonds present in the structure of the complex.

Answer»


Solution :`Ni^(2+) + 2dmg underset (NH_(4)OH) to [Ni(DMG)_(2)] darr` (BRIGHT red).
38.

An alcoholic solution of dimethylglyoxime is added to an aqueous solution of nickel(II) chloride.Slow addition of ammoniam hydroxide led to the precipitation of a bright red colured metal complex. Find out the number of hydrogen bonds present in the structure of the complex.

Answer»


SOLUTION :`NI^(2+)+2dmgoverset(NH_4OH)to[Ni(dmg)_2]DARR`(BRIGHT red )
39.

An alcohol X on heating with concentrated H_(2)SO_(4) gives an alkene Y which can show geometrical isomerism . The alcohol X is

Answer»

`CH_(3)CH_(2)CH(OH)CH_(3)`
`(CH_(3))_(2)C(OH)CH(CH_(3))_(2)`
`(CH_(3))_(3)C(OH)`
`(CH_(3))_(2)C(OH)CH_(2)CH_(3)`

Answer :A
40.

An alcohol (x) gives blue colorin Victormayer's test and 3.7g of X when treated with metallic sodium liberates 560 mL of hydrogen at 273 K and 1 atm pressure what will be the possible structure of X?

Answer»

`CH_(3)CH(OH)CH_(2)CH_(3)`
`CH_(3)-CH(OH)-CH_(3)`
`CH_(3)-C(OH)-(CH_(3))_(2)`
`CH_(3)-CH_(2)-CH(OH)-CH_(2)-CH_(3)`

Solution :`2R-OH+Nato2RONa+2H_(2)uarr` 2 moles of alcohol gives 1 mole of `H_(2)` which occupies 22.4 L at 273 K and 1 ATM
`therefore` number of moles of alcohol = `(2"moles of "R-OH)/(22.4L" of "H_(2))xx560mL=0.05`moles
`therefore` number of moles = `"mass"/("molar mass")RARR"molar mass"=3.7/0.05=74gmol^(-1)`
General formula for `R-OHC_(n)H_(2n+1)-OH`
`thereforen(12)+(2n+1)(1)+16+1=74`
14n = 74 - 18
14n = 56
`thereforen=56/4=4`
The `2^(@)` alcohol which contains 4 carbon is `CH_(3)CH(OH)CH_(2)CH_(3)`
41.

An alcohol (x) gives blue colour in victormayer's test and 3.7 g of X when treated with metallic sodium liberates 500 mLof hydrogen at 273 K and 1 atm pressure what will be the possible structure of X ?

Answer»

`CH_3CH(OH) CH_2CH_3`
`CH_3-CH(OH) - CH_3`
`CH_3-C (OH)-(CH_3)_2`
`CH_3-CH_2-CH(OH) - CH_2-CH_3`

Solution :`2R - OH + Na to 2RONa + 2H_2uarr` 2moles of alcohol gives 1 mole of `H_2` which OCCUPIES
22.4 L at 273 K and 1 ATM
`:.` number of moles of alcohol `=(2"mole of R - OH")/(22.4L " of "H_2)xx560 mL = 0.05"moles"`
`:.` number of moles `=("mass")/("molar mass")rArr "molar mass " = 3.7/0.05 = 74 g MOL^(-1)`
GENERAL formual for `R - OH C_n H_(2n+1)-OH`
`:.n (12) + (2n + 1) (1)+ 16 + 1= 74`
`14n= 74 - 18`
`14 n = 56`
` :. n = 56/4 = 4`
The `2^@` alcohol which contains is `CH_2 CH(OH) CH_2 CH_3`
42.

An alcoholic drink substance pH = 4.7 then OH ion concentration of this solution is (K_(w) = 10^(-14) mol^(2)//l^(2))

Answer»

`3 XX 10^(-10)`
`5 xx 10^(-10)`
`1 xx 10^(-10)`
`5 xx 10^(-8)`

Solution :pH = 4.7
pH + pOH = 14, pH = 14- 4.7 , pOH = 9.3
`[OH^(-)] = "ANTILOG" [-9.3] [OH^(-)] = 5 xx 10^(-10)`.
43.

An alcohol produced during the manufacture of snop is :

Answer»

Butanol
Glycerol
Ethanol
Ethylene glycol

Answer :B
44.

An alcohol on oxidation is found to give CH_(3)COOH and CH_(3)CH(OH)CH_(2)CH_(2)CH_(3) The structure of the alcohol is :

Answer»

`CH_(3)CH_(2)CH_(2)OH`
`(CH_(3))_(2)C(OH)CH_(2)CH_(3)`
`CH_(3)CH_(2)CH(OH)CH_(3)`
`CH_(3)CH(OH)CH_(2)CH_(2)CH_(3)`

ANSWER :D
45.

An alcohol on oxidation is found to give CH_(3)COOH and CH_(3)CH_(2)COOH. The structure to the alcohol is

Answer»

`CH_(3)CH_(2)CH_(2)OH`
`(CH_(3))_(3)C(OH)CH_(2)CH_(3)`
`CH_(3)CH_(2)CHOHCH_(3)`
`CH_(3)CH(OH)CH_(2)CH_(2)CH_(3)`

ANSWER :A
46.

An alcohol on oxidation is found to give CH_3COOH and CH_3CH_2COOH.The alcohol is :

Answer»

`CH_3,CH_2CH_2OH`
`(CH_3)_2C(OH)CH_2CH-3`
`CH_3(CH_2)_2CH_2OH`
`CH_3CH(OH)CH_2CH_2CH_3`

ANSWER :D
47.

An alcohol on alk. KMnO_4 oxidation gives first acetone and on further oxidation acetic acid. It is :

Answer»

ETHYL alcohol
Isopropyl alcohol
primary alcohol
none

Answer :B
48.

An alcohol of molecular formula C_(5)H_(11)OH on dehydration gives an alkene, which on oxidation yields a mixture of ketone and an acid. The alcohol is

Answer»

`CH_(3)CH_(2)(OH)CH_(2)CH_(3)`
`CH_(3) UNDERSET(OH) underset(|)(CHCH_(2))CH_(2)CH_(3)`
`(CH_(3))_(2)CHCH(OH)CH_(3)`
`(CH_(3))_(3)C CH_(2)OH`

Solution :`CH_(3)-overset(CH_(3))overset(|)CH-underset((C_(5)H_(11)OH))underset(OH)underset(|)(CHCH_(3))underset(-H_(2)O)overset(H^(+))toCH_(3)-underset("Alkene")overset(CH_(3))overset(|)C=CHCH_(3)underset(ZN,H_(2)O)overset(O_(3))toCH_(3)-underset("Acetone")overset(CH_(2))overset(|)C=O+underset("Acetic acid")(CH_(3)COOH)`
49.

An alcohol is not oxidised in alkaline or netural solution but in acidic solution it is turned first to acetone and then to acetic acid . It is a :

Answer»

PRIMARY alcohol
Secondary alcohol
Tertiary alcohol
None of these

Answer :C
50.

An alcohol C_4H_9OH on dehydration gives an alkene, which on oxidation yield a acetone. The alcohol is

Answer»

`(CH_3)_3COH`
`CH_3CH_2CH(OH)CH_3`
`CH_3CH_2CH_2CH_2OH`
`(CH_3)_2CHCH_2OH`

Solution :`(CH_3)_3COHoverset("DEHYDRATION")to(CH_3)_2C=CH_2+H_2O`
`(CH_3)_2C=CH_2+4[O] UNDERSET(+dil. H_2SO_4)OVERSET(K_2Cr_2O_7)to CH_3COCH_3 + CO_2 + H_2O`