Author Archives: Priyanka

In This Post we are  providing Chapter-14 Biomolecules  NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON BIOMOLECULES

Question 1 : Which of the following gives positive Fehling solution test?

(a) Protein  (b) Sucrose
(c) Glucose (d) Fats

Answer : C

Question 2: Which of the following statements is incorrect regarding glucose?

(a) It is an aldohexose.
(b) It is also known as dextrose
(c) It is monomer of cellulose.
(d) It is the least abundant organic compound on earth.

Answer : D 

Question 3 : Glucose gives silver mirror test with Tollen’s reagent. It shows the presence of

(a) acidic group   (b) alcoholic group
(c) ketonic group (d) aldehyde group

Answer : D  

Question 4: The symbols D and L represents

(a) the optical activity of compounds.
(b) the relative configuration of a particular stereoisomer.
(c) the dextrorotatory nature of molecule.
(d) the levorotatory nature of molecule

Answer : B 

Question 5:   The function of glucose is to

(a) provides energy  (b) promote growth
(c) prevent diseases (d) perform all above

Answer : A

Question 6 : Which one of the following compounds is different from the rest?

(a) Sucrose (b) Maltose
(c) Lactose (d) Glucose

Answer : D 

Question 7 : The two functional groups present in a typical carbohydrate are:

(a) – CHO and – COOH   (b) > C = O and – OH
(c) – OH and – CHO       (d) – OH and – COOH

Answer : C 

Question 8: When glucose reacts with bromine water, the main product is

(a) gluconic acid   (b) glyceraldehyde
(c) saccharic acid (d) acetic acid

Answer : A 

Question 9: Glucose does not react with

(a) Br₂/H₂O (b) H₂NOH
(c) HI         (d) NaHSO₃

Answer : D 

Question 10: Biomolecules are

(a) aldehydes and ketones
(b) acids and esters
(c) carbohydrates, proteins and fats
(d) alcohols and phenols

Answer : C

Question 11 : Which of the following monosaccharide is pentose ?

(a) Glucose    (b) Fructose
(c) Arabinose (d) Galactose

Answer : C

Question 12: Which one of the following compounds is found abundantly in nature?

(a) Fructose (b) Starch
(c) Glucose  (d) Cellulose

Answer : D

Question 13: A carbohydrate that cannot be hydrolyzed into simpler units is called

(a) polysaccharides (b) trisaccharide
(c) disaccharides    (d) monosaccharides

Answer : D

Question 14 : Which of the following statements is incorrect ?

(a) Maltose gives two molecules of glucose only.
(b) Cellulose and sucrose are polysaccharide.
(c) Polysaccharides are not sweet in taste.
(d) Polysaccharides are also known as non-sugars

Answer : B

Question 15 : Reducing sugars reduce.

(a) only Fehling’s solution
(b) only Tollen’s solution.
(c) both (a) & (b)
(d) neither (a) nor (b)

Answer : C

In This Post we are  providing Chapter-13 Amines  NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON AMINES

Question 1.
Nitrogen atom of amino group is ………. hybridized.
(a) sp
(b) sp²
(c) sp³
(d) sp³d

Answer: (c) sp³

Question 2.
Which of the following should be most volatile?
I. CH₃CH₂CH₂NH₂
II. (CH₃)₃N

IV. CH₃CH₂CH₃
(a) II
(b) IV
(c) I
(d) III

Answer: (b) IV

Question 3.
C₃H₈N cannot represent
(a) 1° ammine
(b) 2° ammine
(c) 3° ammine
(d) quaternary ammonium salt

Answer: (d) quaternary ammonium salt

Question 4.
Identify the correct IUPAC name
(a) (CH₃CH₂)₂NCH₃ = N-Ethyl-N-methylethanamine
(b) (CH₃)₃CNH₂ = 2-methylpropan-2-amine
(c) CH₃NHCH (CH₃)₂ = N-Methylpropan-2-amine
(d) (CH₃)₂CHNH₂ = 2, 2-Dimethyl-N-propanamine

Answer: (a) (CH₃CH₂)₂NCH₃ = N-Ethyl-N-methylethanamine

Question 5.
The most convenient method to prepare primary (i Amine) amine containing one carbon atom less is
(a) Gabriel phthalimide synthesis
(b) Reductive amination of aldehydes
(c) Hofmann bromamide reaction
(d) Reduction of isonitriles

Answer: (c) Hofmann bromamide reaction

Question 6.
Identify the correct pathway to convert propanoic acid to ethylamine. The reagent represented by A, B and C are

Answer: (b)

Question 7.
When excess of ethyl iodide is treated with ammonia, the product is
(a) ethylamine
(b) dimethylamine
(c) triethylamine
(d) tetraethylammonium iodide

Answer: (d) tetraethylammonium iodide

Question 8.
Amides may be converted into amines by a reaction named after
(a) Hofmann Bromide
(b) Claisen
(c) Perkin
(d) Kerulen

Answer: (a) Hofmann Bromide

Question 9.
Reduction of CH₃CH₂NC with hydrogen in presence of Ni or Pt as catalyst gives
(a) CH₃CH₂NH₂
(b) CH₃CH₂NHCH₃
(c) CH₃CH₂NHCH₂CH₃
(d) (CH₃)₃N

Answer: (b) CH₃CH₂NHCH₃

Question 10.
Secondary amines can be prepared by
(a) reduction of nitro compounds
(b) oxidation of N-substituted amides
(c) reduction of isonitriles
(d) reduction of nitriles

Answer: (c) reduction of isonitriles

Question 11.
Which of the following amides will give ethylamine on reaction with sodium hypo bromide?
(a) Butanamide
(b) Propanamide
(c) Acetamide
(d)Benzamide

Answer: (b) Propanamide

Question 12.
Benzoic acid is treated with SOCl₂ and the product (X) formed is reacted with ammonia to give (Y). (Y) on reaction with Br₂ and KOH gives (Z). (Z) in the reaction is
(a) aniline
(b) chlorobenzene
(c) benzamide
(d) benzoyl chloride

Answer: (a) aniline

Question 13.
Which one of the following reducing agents is likely to be most effective in bringing about the following change?

(a) H₂-Ni
(b) NaBH₄
(c) LiAlH₄ ether
(d) Na-Alcohol

Answer: (c) LiAlH₄ ether

Question 14.
Amine that cannot be prepared by Gabricl-Phthalmidie synthesis is
(a) aniline
(b) benzyl amine
(c) methyl amine
(d) iso-butylamine

Answer: (a) aniline

Question 15.
What is the end product in the following sequence of reactions?

(a) Aniline
(b) Phenol
(c) Benzene
(d) Benzenediazxonium chloride

Answer: (a) Aniline

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In This Post we are  providing Chapter-12 Aldehyde, Ketones and Carboxylic acids  NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ALDEHYDE, KETONES AND CARBOXYLIC ACIDS

1) Which of the following carbonyl compound is used in the preparation of ice cream? 

a) berzophenone

b) acetophenone

c) acetone

d) acetaldehyde

Answer- : b

2) The polar nature of carbonyl group in aldehydes and ketones is due to____________

a) very less electronegative difference

b) very large electronagative difference

c) presence ot hydrogen bonding

d) presence of sp hybridised characters in carbonyl compound

Answer- : b

3) Which of the following organic compounds are second oxidation products of alkanes?

a) 1°and 2° alcohols

b) carboxylic acids and esters

c) 2° and 3° alcohols

d) aldehyde and ketones

Answer- : d

4) phenones are_________

a) aldehyde in which carbonyl group is attached with benzene ring

b) ketone in which carbonyl group is attached with benzene ring

c) phenols in which carbonyl group is attached with alkyl group 

d) phenols in which carbonyl group is attached with group

Answer- : b

5) Mesity oxide is _________

a) condensation product of acetaldehyde

b) addition product of acetaldehyde nd ammonia 

C) addition product of acetone and ammonia 

d) condensation product of acetone

Answer- : d

6) The dihalide Cl-CH2- CH2- CH2- Cl is _______

a) vicinal dihalide

b) nonterminal geminal dihalide

C) terminal geminal

d) polymethylene dihalide

Answer- : c

7) In IUPAC system

is named as_________

a) naphthalene aldehyde

b) naphthalene carbaldehyde

C) dibenzene aldehyde

d) naphanal

Answer- : b

8) what is the IUPAC name of compound when carbonyl atom carbon atom is attached to Phenyl group and ethyl group

a) propanone benzene

b) phenyl propan- 1-one

c) 2 phenyl propan- 1-one

d) propiophenone

Answer- : c

9) Give the IUPAC name________

CH3- CH2-CH__ CH-CH2-CH3

                   |        |

                 CHO- CH3

a) 4-methyl-2-ethyl pentanal

b) 4-ethyl-3-methyl pentanal

c) 2-ethy-3-methyl pentanal

d )4-methyl hexanal

Answer- : c

10) The IUPAC name of the compound

CH3CH(OH)CH2CH(CH3)CHO is_____

a) 3-hydroxy-1-methyl pentanal

b) 4-hydroxy-Z-methyl pentanal

c) 3-hydroxy-f-methyl pentanal

d 4-hydroxy-3-methyl pentanal

Answer- : b

11) The IUPAC name of the compound, CCl3, CHO is

a) chloral

b) trichloroacetaldehyde

c) 1,1,1-trichloro ethanal

d) 2,2,2-trichloro ethanal

Answer- : d

12) The lUPAC name of methyl iso-propyl ketone is________

a) 3-methyl butan-2-one

b) 2-methyl butan-1-one

c) 3-methyl butan-1-one

d) 1,1-dimethyl-2-one

Answer- : a

13) In aldehydes and ketones the carbonyl carbon is_________

a) sp3-hybridised

b) sp2′ hybridised

c) unhybridised

d)sp-hybridised

Answer- : b

14) Polar nature of >C=0 group in aldehydes and ketones results ______

a) intemolecular association

b) hydrogen bonding

c) intermolecular H-bonding

d) intramolecular H-bonding

Answer -: a

15) which of the following decrease the reactivity of aldehyde?

a)+I effect

b) -Ieffect

c) positive electromeric effect

d) negative electromeric effect

Answer -: a

In This Post we are  providing Chapter-11 Alcohols, Phenols, and Ethers NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ALCOHOLS, PHENOLS AND ETHERS

Question 1.
Which of the following alcohols gives 2-butenc on dehydration by conc. H₂SO₄?
(a) 2-methyl propene-2-ol
(b) 2-methyl 1 -propanol
(c) Butane-2-ol
(d) Butane 1-ol

Answer: (c) Butane-2-ol

Question 2.
One mole of ethyl acetate on titmen with an excess of LiAlH₄ in dry ether and subsequent acidification produces
(a) 1 mole acetic acid + 1 mole ethyl alcohol
(b) 1 mole ethyl alcohol + 1 mole methyl alcohol
(c) 2 moles of ethyl alcohol
(d) 1 mole of 2-butanol

Answer: (c) 2 moles of ethyl alcohol

Question 3.
Which of the following reagents can not, be used to oxidise primary alcohols to aldehydes?
(a) CrO₃ in anhydrous medium
(b) KMnO₄ in acidic medium
(c) Pyridinium chlorochromate
(d) Heat in the presence of Cu at 573 K

Answer: (b) KMnO₄ in acidic medium

Question 4.
1-Phenylethanol can be prepared by the reaction of benzaldehyde with
(a) methyl bromide
(b) ethyl iodide and magnesium
(c) methyl iodide and magnesium (Grignard reagent’s)
(d) methyl bromide and aluminum bromide

Answer: (c) methyl iodide and magnesium (Grignard reagent’s)

Question 5.
Which of the following alcohols will give the most stable carbocation during dehydration?
(a) 2-methyl-1-propanol
(b) 2-methyl-2-propanol
(c) 1-Butanol
(d) 2-Butanol

Answer: (b) 2-methyl-2-propanol

Question 6.
A compound X with the molecular formula C₂H₈O can be oxidized to another compound Y whose molecular formulae is C₃H₆O₂. The compound X may be
(a) CH₃CH₂OCH₃
(b) CH₃CH₂CHO
(c) CH₃CH₂CH₂OH
(d) CH₃CHOHCH₃

Answer: (c) CH₃CH₂CH₂OH

Question 7.
Order of esterification of alcohols are
(a) 3° > 1° > 2°
(b) 2°> 3° > 1°
(c) 1 ° > 2° > 3°
(d) None of these

Answer: (c) 1 ° > 2° > 3°

Question 8.
What happens when tertiary butyl alcohol is passed over heated copper at 300°C?
(a) Secondary butyl alcohol is formed
(b) 2-methylpropene is formed
(c) 1-butene is formed
(d) Butanol is formed

Answer: (b) 2-methylpropene is formed

Question 9.
Which of the following compounds will be most easily attacked by an electrophile?

Answer: (c)

Question 10.

In the reaction, X is
(a) (CH₃)₂C = CHCH₃
(b) CH₃C = CH
(c) (CH₃)₂CHCH₂CH₃

Answer: (a) (CH₃)₂C = CHCH₃

Question 11.
What would be the reactant and reagent used to obtain 2, 4-dimenthyl pentan-3-ol?
(a) Propanal and propyl magnesium bromide
(b) 3-methylbutanal and 2-methyl magnesium iodide
(c) 2-dimethylpropanone and methyl magnesium iodide
(d) 2-methylpropanal and isopropyl magnesium iodide

Answer: (d) 2-methylpropanal and isopropyl magnesium iodide

Question 12.
The decreasing order of boiling point of the following alcohols is
(a) 3-methylbuan-2-ol > 2-methylbutan-2-ol > pentan-1-ol
(b) Pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol
(c) 2-methylbutan-2-ol > 3-methylbutan-2-ol > pentan-1-ol
(d) 2-methylbutan-2-ol > pental-1-ol > 3-methylbutan-2-ol

Answer: (b) Pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol

Question 13.
Acid catalyzed dehydration of t-butanol is faster than that of n-butanol because
(a) tertiary carbocation is more stable than primary carbocation
(b) primary carbocation is more stable than tertiary carbocation
(c) t-butanol has a higher boiling point
(d) rearrangement takes place during dehydration of t- butanol

Answer: (a) tertiary carbocation is more stable than primary carbocation

Question 14.
An unknown alcohol is treated with “Lucas reagent” to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism?
(a) Tertiary alcohol by S_N²
(b) Secondary alcohol by S_N¹
(c) Tertiary alcohol by S_N¹
(d) Secondary alcohol by S_N²

Answer: (c) Tertiary alcohol by S_N¹

Question 15.
An alcohol X when treated with hot cone. H₂SO₄ gave an alkene Y with formula C₄H₈. This alkene on ozonolysis gives single product with molecular formula C₂H₄O. The alcohol is
(a) butan-1-ol,
(b) butan-2-ol
(c) 2-methylpropan-1-ol
(d) 2,2-dimethylbutynal-1-oI

Answer: (b) butan-2-ol

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In This Post we are  providing Chapter-10 Haloalkanes and Haloarenes  NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON HALOALKANES AND HALOARENES

Question 1.
Good conductor of electricity and heat is
(a) Anthracite coke
(b) Diamond
(c) Graphite
(d) Charcoal

Answer: (c) Graphite

Question 2.
In which of the following allotropes of carbon, percentage of carbon is maximum?
(a) Wood charcoal
(b) Coconut charcoal
(c) Graphite
(d) None of these

Answer: (c) Graphite

Question 3.
The hybridization of carbon in diamond is
(a) sp³
(b) sp²
(c) sp
(d) dsp²Answer

Answer: (a) sp³

Question 4.
Organic compound must contain an element
(a) oxygen
(b) carbon
(c) hydrogen
(d) nitrogen

Answer: (b) carbon

Question 5.
Alkene gives which of the following reactions?
(a) Addition reaction
(b) Substitution reaction
(c) Both (a) and (b)
(d) None of these

Answer: (c) Both (a) and (b)

Question 6.
Single bond length between carbon-carbon is
(a) 1.34 Å
(b) 1.20 Å
(c) 1.54 Å
(d) none of these

Answer: (c) 1.54 Å

Question 7.
Valency of carbon is
(a) 1
(b) 2
(c) 3
(d) 4

Answer: (d) 4

Question 8.
Criteria for purity of organic solid is
(a) boiling point
(b) melting point
(c) specific gravity
(d) none of these

Answer: (b) melting point

Question 9.
General formula of Alkene is
(a) C_nH_2n
(b) C_nH_2n+2
(c) C_nH_2n-2
(d) none of these

Answer: (a) C_nH_2n

Question 10.
Hybridization of carbon in ethane is
(a) sp³
(b) sp²
(c) sp
(d) sp³d²

Answer: (a) sp³

Question 11.
Number of π bonds in ethyne is
(a) 1
(b) 2
(c) 3
(d) 4

Answer: (b) 2

Question 12.
The compound having general formula C_nH_2n+2 is
(a) Alkene
(b) Alkyne
(c) Alkane
(d) none of these

Answer: (c) Alkane

Question 13.
Which of the following is not correctly matched with its IUPAC name?
(a) CHF₂CBrClF : 1-Bromo-1-chIoro-1, 2, 2-trifluoroethane
(b) (CCl₃)₃CCl : 2-(Trichloromethyl)-1, 1, 2, 3, 3-heptachloropropane
(c) CH₃C (p-ClC₆H₄)₂CH(Br)CH₃ : 2-Bromo-3, 3-bis (4- chlorophenyl) butane
(d) o-BrC₆H₄CH (CH₃) CH₂CH₃ : 2-Bromo-l- methylpropylbenzene

Answer: (b) (CCl₃)₃CCl : 2-(Trichloromethyl)-1, 1, 2, 3, 3-heptachloropropane

Question 14.
The negative part of the addendum (the molecule to be added) adds on the carbon atom of the double bond containing the least number of hydrogen atoms. This rule is known as
(a) Saytzeffs rule
(b) Peroxide rule
(c) Markovnikov’s rule
(d) Van’t Hoff rule

Answer: (c) Markovnikov’s rule

Question 15.
Which of the following compounds can yield only one monochlorinated product upon free radical chlorination?
(a) 2, 2-Dimethylpropane
(b) 2-Methylpropane
(c) 2-Methylbutane
(d) n-Butane

Answer: (a) 2, 2-Dimethylpropane

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In This Post we are  providing Chapter-9 Coordination Compounds NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON COORDINATION COMPOUNDS

1. The sum of coordination number of oxidation number of the metal M in the complex [M(en)2 C204] Cl are
(a) 7
(b) 8
(c) 9
(d) 6

Answer: c

2. Which of the following will not give test for Cl^– with AgNO₃(aq) at 25°C?
(a) COCl3.5NH3
(b) COCl3.6NH3
(c) COCl3.3NH3
(d) COCl3.4NH3

Answer: c

3. Which of these statements about [Co(CN)₆]^3- is true?
(a) It has 4 unpaired electron, high spin
(b) No unpaired electron, high spin
(c) No unpaired electron, low spin
(d) 4 unpaired electron, low spin

Answer: c

4. The correct order of the stoichiometry’s of AgCl formed when AgNO₃ in excess is treated with complexes: COCl₃.6NH₃, C0Cl₃.5NH₃, C0Cl₃.4NH₃ respectively is
(a) 3AgCl, lAgCl, 2AgCl
(b) 3AgCl, 2AgCl, 1AgCl
(c) 2AgCl, 3AgCl, 2AgCl
(d) lAgCl, 3AgCl, 2AgCl

Answer: b

5. Correct increasing order of wavelength of absorption in visible region for complex of Co³⁺ is

Answer: d

6. Pick out the correct statement with respect to [Mn(CN)J2-
(a) It is sp²d² hybridized, tetrahedral
(b) It is d²sp³ hybridized, octahedral
(c) It is dsp² hybridized, square planar
(d) It is sp³d² hybridized octahedral

Answer: b

7. Facial and meridional isomerism will be shown by
(a) [Co(NH₃)₃Cl₃]
(b) [Co(NH₃)₄Cl₂] Cl
(c) [Co(en)₃] Cl₃
(d) [Co(NH₃)₅Cl] Cl₂

Answer: a

8. Which one has highest molar conductivity?
(a) [Pt(NH₃)₂ Cl₂]
(b) [CO(NH₃)₄ Cl₂] Cl
(c) K₄[Fe(CN)₆]
(d) [Cr(H₂O)₆] Cl₃

Answer: c

9. Which one will show optical isomerism?
(a) [Co(NH₃)₃Cl₃]
(b) cis-[Co(en)₂ Cl₂] Cl
(c) trans-[Co(en)₂ Cl₂] Cl
(d) [Co(NH₃)₄ Cl₂] Cl

Answer: b

10. The pair having the same magnetic moment is (At No. Cr = 24, Mn = 25, Fe = 26, Co = 27)
(а) [Cr(H₂O)₆]²⁺ and [CoCl₄]^2-
(b) [Cr(H₂O)₆]²⁺ and [Fe (H₂O)₆]²⁺
(c) [Mn(H₂O)₆]²⁺ and[Cr(H₂O)₆]²⁺
(d) [COCl₄]^2- and [Fe(H₂O)₆]²⁺

Answer: b

11. On treatment of 100 mL of 0.1 MCOCl₃.6H₂O with excess of AgNO₃, 1.2 × 10²² ions are precipitated. The complex is
(a) [Co(H₂O)₄Cl₂]Cl.2H₂O
(b) [Co(H₂O)₃Cl₃]3H₂O
(c) [Co(H₂O)₆] Cl₃
(d) [Co(H₂O)₅ Cl] Cl₂.H₂O

Answer: d

12. Among the ligands NH3, en, CN and CO, the correct order of field strength is
(a) NH₃ < en < CN^– < CO
(b) CN^– < NH₃ < CO < en
(c) en < CN^–< NH₃ < CO
(d) CO < NH₃ < en < CN^–

Answer: a

13. Which of the following complexes formed by Cu²⁺ ions is most stable?

Answer: b

14. The stabilization of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?
(a) [Fe(CO)₅]
(b) [Fe(CN)₆]^3-
(c) [Fe(C₂O₄)₃]^3-
(d) [Fe(H₂O)₆]³⁺

Answer: c

15. Indicate the complex ion which shows geometrical isomerism.
(a) [Cr(H₂O)₄Cl₂]⁺
(b) [Pt(NH₃)₃ Cl]
(c) [Co(NH₃)₆]³⁺
(d) [Co(CN)₅(NC)]^3-

Answer: a

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In This Post we are  providing Chapter-8 The d and f-Block Elements NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON THE d AND f-BLOCK ELEMENTS

Question 1.
Oxidation number of gold metal is
(a) +1
(b) 0
(c) -1
(d) all of these

Answer: (a) +1

Question 2.
Shape of d-orbital is
(a) spherical
(b) dumb bell
(c) double dumb bell
(d) none of these

Answer: (c) double dumb bell

Question 3.
Electronic configuration of alkaline earth element is
(a) ns²
(b) ns¹
(c) np⁶
(d) ns⁰

Answer: (a) ns²

Question 4.
Lanthanoid contraction is due to increase in
(a) atomic number
(b) effective nuclear charge
(c) atomic radius
(d) valence electrons

Answer: (b) effective nuclear charge

Question 5.
Which one of the following is called green vitriol?
(a) FeSO₄ 7H₂O
(b) CuSO₄ 5H₂O
(c) CaSO₄ 2H₂O
(d) None of these

Answer: (a) FeSO₄ 7H₂O

Question 6.
Which block of elements are known as transition elements?
(a) p-block
(b) s-block
(c) d-block
(d) f-block

Answer: (c) d-block

Question 7.
Most abundant element in earth’s crust is
(a) Si
(b) Al
(c) Zn
(d) Fe

Answer: (a) Si

Question 8.
Which one of the following is diamagnetic ion?
(a) Co²⁺
(b) Ni²⁺
(c) Cu²⁺
(d) Zn²⁺

Answer: (d) Zn²⁺

Question 9.
Which of the following is not an element of first transition series?
(a) Iron
(b) Chromium
(c) Magnesium
(d) Nickel

Answer: (c) Magnesium

Question 10.
The correct order of EM2+/M0 values with negative sign for the four successive elements Cr, Mn, Fe and Co is
(a) Fe > Mn > Cr > Co
(b) Cr > Mn > Fe > Co
(c) Mn > Cr > Fe > Co
(d) Cr > Fe > Mn > Co

Answer: (c) Mn > Cr > Fe > Co

Question 11.
The number of unpaired electrons in gaseous species of Mn³⁺, Cl³⁺ and V³⁺ respectively are and the most stable species is
(a) 4, 3 and 2; V³⁺
(b) 3, 3 and 2; Cr³⁺
(c) 4, 3 and 2; Cr³⁺
(d) 3, 3 and 3; Mn³⁺

Answer: (c) 4, 3 and 2; Cr³⁺

Question 12.
Fe³⁺ ion is more stable than Fe²⁺ ion because
(a) more the charge on the atom, more is its stability
(b) configuration of Fe²⁺ is 3d⁵ while Fe³⁺ is 3d⁵
(c) Fe²⁺ has a larger size than Fe³⁺
(d) Fe³⁺ ions are colored hence more stable

Answer: (b) configuration of Fe²⁺ is 3d⁵ while Fe³⁺ is 3d⁵

Question 13.
Color of transition metal ions are due to absorption of some wavelength. This results in
(a) d-s transition
(b) s-s transition
(c) s-t/transition
(d) d-d transition

Answer: (d) d-d transition

Question 14.
Which group contains colored ions out of the following?
1. Cu^–. 2. Ti^4- 3. Co²⁺ 4. Fe^2-
(a) 1, 2, 3, 4
(b) 3, 4
(c) 2, 3
(4) 1, 2

Answer: (b) 3, 4

Question 15.
The melting points of Cu, Ag and Au follow the order
(a) Cu > Ag > Au
(b) Cu >Au > Ag
(c) Au > Ag > Cu
(d) Ag > Au > Cu

Answer: (b) Cu >Au > Ag

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In This Post we are  providing Chapter-7 The p-Block Elements NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON THE p-BLOCK ELEMENTS

1. Among the following, which one is a wrong statement.
(a) PH₅ and BiCl₅ do not exist.
(b) pπ-dπ bonds are present in SO₂
(c) SeF₄ and CH₄ have same shape.
(d) I₃ has bent geometry.

Answer: c

2. In which of the pair of ions, both species contain S—S bond?

Answer: a

3. Which one of the following order is correct for the bond dissociation enthalpy of halogen molecule?
(a) Br₂ > I₂ > F₂ > Cl₂
(b) F₂ > Cl₂ > Br₂ > I₂
(c) I₂ > Br₂ > Cl₂ > F₂
(d) Cl₂ > Br₂ > F₂ > I₂

Answer: d

4. Which is strongest acid in the following:
(a) HClO₄
(b) H₂SO₃
(c) H₂SO₄
(d) HClO₃

Answer: a

5. In which of the following pairs, the two species are isostructural

Answer: c

6. The correct order of oxidizing power is
(a) HClO₄ > HClO₃ > HClO₂ > HCIO
(b) HOCl > HClO₂ > HClO₃ > HClO₄
(c) HClO₃ > HClO₄ > HClO₂ > HClO
(d) HCIO₂ > HOCl > HClO₃ > HClO₄

Answer: b

7. The correct order of acid strength is
(a) HClO₄ < HClO₃ < HClO₂ < HClO
(b) HCIO < HClO₂ < HClO₃ < HClO₄
(c) HClO₄ < HClO < HClO₂ < HClO₃
(d) HClO₂ < HClO₃ < HClO₄ < HClO

Answer: b

8. Among the following which is strongest oxidizing agent.
(a) Br₂
(b) I₂
(c) Cl₂
(d) F₂

Answer: d

9. The correct order of bond angles in the following species is

Answer: b

10. Sulphur trioxide can be obtained by which of the following:

Answer: (b)

11. When Cl₂ reacts with hot and cone. NaOH, the oxidation number of chlorine changes from
(a) zero to +1 and zero to +5
(b) 0 to -1 and 0 to +5
(c) zero to -1 and zero to +3
(d) 0 to +1 and 0 to -3

Answer: b

12. Acidity of diprotic acid in aqueous solution increases in the order.
(a) H₂S < H₂Se < H₂Te
(b) H₂Se < H₂S < H₂Te
(c) H₂Te < H₂S < H₂Se
(d) H₂Se < H₂Te < H₂S

Answer: a

13. Which of the following statement is incorrect?
(a) ONF is isoelectronic with NO^–₂
(h) OF₂ is an oxide of fluoride
(c) Cl₂O₇ is an anhydride of perchloric acid
(d) O₃ molecule is bent

Answer: b

14. Chlorine reacts with excess of NH₃ to form
(a) NH₄Cl
(b) N₂ + HCl
(c) N₂ + NH₄Cl
(d) NCl₃ + HCl

Answer: c

15. Which of the following reactions is an example of redox reaction?
(a) XeF₄ + O₂F₂ → XeF₆ + O₂
(b) XeF₂ + PF₅ → [XeF]⁺ [PF₆]^–
(c) XeF₆ + H₂O → XeOF₄ + 2HF

Answer: a

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In This Post we are  providing Chapter-6 General Principles and Processes of Isolation of Elements NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS

Question 1.
Concentration of sulphide ore is done by
(a) froth flotation process
(b) electrolysis
(c) roasting
(d) None of these

Answer: (a) froth flotation process

Question 2.
Malachite is an ore of
(a) iron
(b) copper
(c) zinc
(d) Sliver

Answer: (b) copper

Question 3.
Formula of copper pyrite is
(a)Cu₂S
(b) CuFeS
(c) CuFeS₂
(d) Cu₂Fe₂S₂

Answer: (c) CuFeS₂

Question 4.
Ore of aluminum is
(a) bauxite
(b) hematite
(c) dolomite
(d) None of these

Answer: (a) bauxite

Question 5.
Removal of the unwanted materials like sand, clays, etc. from the ore is known as ………., …….. or ……….
(a) concentration, dressing, benefaction
(b) separation, refining, gangue
(c) magnetic separation, purification, gangue
(d) washing, refining, amalgamation

Answer: (a) concentration, dressing, benefaction

Question 6.
For which of the following ores froth floatation method is used for concentration?
(a) Hematite
(b) Zinc blende
(c) Magnetite
(d) Camallite

Answer: (b) Zinc blende

Question 7.
The powdered ore is agitated with water or washed with running stream of water. The heavy ore particles and lighter impurities are separated. This method of concentration is known as
(a) metallurgy
(b) leaching
(c) froth floatation process
(d) gravity separation

Answer: (d) gravity separation

Question 8.
The oil used as frothing agent in froth floatation process is
(a) coconut oil
(b) castor oil
(c) palmitic oil
(d) pine oil

Answer: (d) pine oil

Question 9.
Which of the following metals is not extracted by leaching?
(a) Aluminum
(b) Mercury
(c) Silver
(d) Gold

Answer: (b) Mercury

Question 10.
Sulphide ore of zinc/copper is concentrated by
(a) floatation process
(b) electromagnetic process
(c) gravity separation
(d) distillation

Answer: (a) floatation process

Question 11.
Which of the following ores is concentrated by chemical leaching method?
(a) Cinnabar
(b) Argentite
(c) Copper pyrites
(d) Galena

Answer: (b) Argentite

Question 12.
How do we separate two sulphide ores by froth floatation method?
(a) By using excess of pine oil
(b) By adjusting proportion of oil to water or using depressant.
(c) By using some solvent in which one of the sulphide is soluble
(d) By using collectors and froth stabilizers like xanthates

Answer: (b) By adjusting proportion of oil to water or using depressant.

Question 13.
Common impurities present in bauxite are
(a) CuO
(b) ZnO
(c) CaO
(d) SiO₂

Answer: (d) SiO₂

Question 14.
An ore of tin containing FeCrO₄ is concentrated by
(a) gravity separation
(b) magnetic separation
(c) froth floatation
(d) leaching

Answer: (b) magnetic separation

Question 15.
Which of the following ores cannot be concentrated by magnetic separation?
(a) Hematite
(b) Malachite
(c) Magnetite
(d) Siderite

Answer: (b) Malachite

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In This Post we are  providing Chapter-5 Surface Chemistry NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON SURFACE CHEMISTRY

Question 1.
Movement of dispersion medium under the influence of electric field is known as
(a) electrodialysis
(b) electrophoresis
(c) electro osmosis
(d) cataphoresis.

Answer: (c) electro osmosis

Question 2.
At CMC (Critical Micellization Cone.) the surface molecules
(a) associate
(b) dissociate
(c) decompose
(d) become completely soluble.

Answer: (a) associate

Question 3.
Milk is an example of
(a) emulsion
(b) suspension
(c) foam
(d) sol.

Answer: (a) emulsion

Question 4.
Tyndall effect is due to
(a) electric charge
(b) scattering of light
(c) absorption of light
(d) none of these.

Answer: (b) scattering of light

Question 5.
Fog is a colloidal system of
(a) liquid dispersed in a gas
(b) gas dispersed in a gas
(c) solid dispersed in gas
(d) solid dispersed in liquid

Answer: (a) liquid dispersed in a gas

Question 6.
Blood may be purified by
(a) coagulation
(b) dialysis
(c) electro-osmosis
(d) filtration

Answer: (b) dialysis

Question 7.
Blue color of water in sea is due to
(a) refraction of blue light by impurities in sea water
(b) scattering of light by water
(c) refraction of blue sky by water
(d) None of these

Answer: (a) refraction of blue light by impurities in sea water

Question 8.
The cause of Brownian movement is
(a) heat change in liquid state
(b) attractive force between colloidal particles and dispersion medium
(c) bombardment of the colloidal particles by the molecules of the dispersion medium
(d) interaction of charged particles

Answer: (c) bombardment of the colloidal particles by the molecules of the dispersion medium

Question 9.
Emulsifying agent present in milk that makes it stable is
(a) maltose
(b) casein
(c) lactose
(d) none of these

Answer: (b) casein

Question 10.
Cloud is an example of
(a) liquid dispersed in gas
(b) solid dispersed in gas
(c) solid dispersed in liquid
(d) none of these

Answer: (a) liquid dispersed in gas

Question 11.
The color of sky is due to
(a) absorption of light
(b) transmission of light
(c) scattering of light
(d) all of these

Answer: (c) scattering of light

Question 12.
Which of the following is lyophobic colloid?
(a) Starch in water
(b) Gum in water
(c) Soap in water
(d) Gold sol

Answer: (d) Gold sol

Question 13.
At high concentration of soap in water, soap behaves as
(a) molecular colloid
(b) associated colloid
(c) macro molecular colloid
(d) lyophilic colloid

Answer: (b) associated colloid

Question 14.
The efficiency of a protective colloid is described in terms of
(a) gold number
(b) flocculation number
(c) valence of counter ion
(d) Tyndall effect.

Answer: (a) gold number

Question 15.
The function of enzymes in the living system is to
(a) maintain pH
(b) catalyze biochemical process
(c) provide immunity
(d) transport oxygen

Answer: (b) catalyze biochemical process

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