MCQ Questions for Class 11 Chemistry Chapter 12 Organic Chemistry: Some Basic Principles and Techniques with Answers

Students are advised to practice the NCERT MCQ Questions for Class 11 Chemistry Chapter 12 Organic Chemistry: Some Basic Principles and Techniques with Answers Pdf free download is available here. MCQ Questions for Class 11 Chemistry with Answers are prepared as per the Latest Exam Pattern. Students can solve these Organic Chemistry: Some Basic Principles and Techniques Class 11 MCQs Questions with Answers and assess their preparation level.

Organic Chemistry: Some Basic Principles and Techniques Class 11 MCQs Questions with Answers

Solving the Organic Chemistry: Some Basic Principles and Techniques Multiple Choice Questions of Class 11 Chemistry Chapter 12 MCQ can be of extreme help as you will be aware of all the concepts. These MCQ Questions on Organic Chemistry: Some Basic Principles and Techniques Class 11 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. Have a glance at the MCQ of Chapter 12 Chemistry Class 11 and cross-check your answers during preparation.

Question 1.
Which among the following statement is not true?
(a) In liquid, particles are less regularly arranged and are free to move
(b) Boiling involves breaking up of group of molecules in liquid
(c) Boiling involves separation of oppositely charged ions
(d) Thermal energy of particles overcome cohesive forces that hold them

Answer

Answer: (c) Boiling involves separation of oppositely charged ions
Explanation:
Boiling involves separation of oppositely charged ions and makes them as individual ions.


Question 2.
Identify the chiral molecule among the following:
(a) Isopropyl alcohol
(b) 2-pentanol
(c) 1-bromo 3-butene
(d) Isobutyl alcohol

Answer

Answer: (d) Isobutyl alcohol
Explanation:
Chirality is the condition for a molecule to be optically active and here isobutyl alcohol is the only compound is optically active and hence it is the chiral molecule.


Question 3.
Which element is estimated by Carius method
(a) Carbon
(b) Hydrogen
(c) Halogen
(d) Nitrogen

Answer

Answer: (c) Halogen
Explanation:
Halogen element is estimated by Carius method


Question 4.
A solution of(+) – 2 – chloro – 2 – phenylethane in toluene racemises slowly in the presence of small amounts of SbCl5 due to the formation of
(a) Carbanion
(b) Carbene
(c) Free radical
(d) Carbocation

Answer

Answer: (d) Carbocation
Explanation:
SbCl5 pulls Cl to form SbCl6 leaving behind planar C6H5−C+H−CH3 carbonium ion. It can be attacked from either side leading to racemic mixture.


Question 5.
Which of the following acids has the smallest dissociation constant?
(a) CH3CHFCOOH
(b) FCH2CH2COOH
(c) BrCH2CH2COOH
(d) CH3CHBrCOOH

Answer

Answer: (c) BrCH2CH2COOH
Explanation:
BrCH2CH2COOH is least acidic or has less Ka i.e., dissociation constant. It is A due to lesser -I effect of Br than F and B Br atom further away form −COOH group.


Question 6.
What is the correct IUPAC name of
MCQ Questions for Class 11 Chemistry Chapter 12 Organic Chemistry Some Basic Principles and Techniques with Answers 1
(a) 4-methoxy-2-nitrobenzaldehyde
(b) 4-formyl-3-nitro anisole
(c) 4-methoxy-6-nitrobenzaldehyde
(d) 2-formyl-5-methoxy nitrobenzene

Answer

Answer: (a) 4-methoxy-2-nitrobenzaldehyde
Explanation:
IUPAC name is 4-methoxy-2-nitrobenzaldehyde
MCQ Questions for Class 11 Chemistry Chapter 12 Organic Chemistry Some Basic Principles and Techniques with Answers 2


Question 7.
0.5 g of hydrocarbon gave 0.9 g water on combustion. The percentage of carbon in hydrocarbon is
(a) 75.8
(b) 80.0
(c) 56.6
(d) 28.6

Answer

Answer: (b) 80.0
Explanation:
Percentage% of H =(2/18) × [(weight of H2O)/(weight of organic compound)] × 100
=(2/18) × [(0.9)/(0.5)] × 100 = 20
Since percentage of hydrogen is 20. Therefore, remaining is carbon i.e. 80 %.


Question 8.
0.92 g of an organic compound was analysed by combustion method. The mass of the U- tube increased by 1.08 g. What is the percentage of hydrogen in the compound?
(a) 13.04%
(b) 52.17%
(c) 65.21%
(d) 11.30%

Answer

Answer: (a) 13.04%
Explanation:
For Percentage % of H,
(Percentage % of H)/(H2O) = (2/18) × [(weight x H2O)/Weight of organic compound)] × 100
= (2/18) × (1.08/0.92) × 100
= 13.04 %


Question 9.
What is the state of hybridisation of carbon in carbanion?
(a) sp
(b) sp²
(c) sp³
(d) sp²d.

Answer

Answer: (c) sp³
Explanation:
In carbanion the carbon atom is sp³ hybridised and the geometry is pyramidal.


Question 10.
An organic compound contains C = 38.8 H = 16 and N = 45.2. Empirical formula of the compound is
(a) CH3NH2
(b) CH3CN
(c) C2H5CN
(d) CH2(NH)2

Answer

Answer: (a) CH3NH2


Question 11.
59 g of an amide obtained from a carboxylic acid, RCOOH, liberated 17 g of ammonia upon heating with alkali. The acid is
(a) Formic Acid
(b) Acetic Acid
(c) Propionic Acid
(d) Benzoic Acid

Answer

Answer: (b) Acetic Acid


Question 12.
The displacement of electrons in a multiple bond in the presence of attacking reagent is called
(a) Inductive effect
(b) Electromeric effect
(c) Resonance
(d) Hyper conjugation

Answer

Answer: (b) Electromeric effect
Explanation:
The electromeric effect is a temporary effect brought into play at the requirement of attacking reagent. Electromeric effect refers to a molecular polarizability effect occurring by an intra-molecular electron displacement. It is the temporary effect.


Question 13.
The molecular formula C5H12 contains how many isomeric alkanes?
(a) 1
(b) 2
(c) 3
(d) 4

Answer

Answer: (c) 3
Explanation:
n-pentane, 2-ethylpropane, and 2-methylbutane are the 3 isomeric alkanes of C5H1 (pentane).


Question 14.
If two compounds have the same empirical formula but different molecular formula they must have
(a) Different percentage composition
(b) Different molecular weight
(c) Same viscosity
(d) Same vapour density

Answer

Answer: (b) Different molecular weight
Explanation:
If molecular formula is different than molecular weight is also different.


Question 15.
Inductive effect involves
(a) displacement of σ electrons
(b) delocalization of π electrons
(c) delocalization of σ-electrons
(d) displacement of π-electrons

Answer

Answer: (a) displacement of σ electrons
Explanation:
During inductive effect shifting of a electrons takes place due to which partially charges are developed on the atom.
+δ” + δ′ + δ −δ
C− C− C −C1−


Question 16.
A gas mixture contains 50% helium and 50% methane by volume. What is the percent by weight of methane in the mixture
(a) 75%
(b) 50%
(c) 80.03%
(d) 19.97%

Answer

Answer: (c) 80.03%
Explanation:
Given the Solution contains He + CH4
Their molecular weight = 4 + 16 = 20 % wt of CH4
= (weight of CH4)/(Total wt × 100)
= (16/20) × 100
= 80.0


Question 17.
Which of the following physical properties differ for each of a pair of enantiomers?
(a) solubility in ethanol
(b) direction of rotation of plane-polarized light
(c) boiling point and melting point
(d) index of refraction

Answer

Answer: (b) direction of rotation of plane-polarized light
Explanation:
Enantiomers are equal in all their physical properties except for their optical rotation, as they rotate the plane of polarized light by equal amounts in opposite directions.


Question 18.
The reaction of HCOOH with conc.H2SO4 gives which of the following compound?
(a) CO2
(b) CO
(c) Oxalic Acid
(d) Acetic acid

Answer

Answer: (b) CO


Question 19.
What is the state of hybridisation of carbon in carbanion?
(a) sp
(b) sp²
(c) sp³
(d) sp²d.

Answer

Answer: (c) sp³
Explanation:
In carbanion the carbon atom is sp³ hybridised and the geometry is pyramidal.


Question 20.
Which among the following is formed when an alcohol is dehydrated?
(a) alkane
(b) alkyne
(c) alkene
(d) aldehyde

Answer

Answer: (c) alkene
Explanation:
In elimination reaction, when protic acids react with alcohol, they lose water molecule to form alkenes.


Hope the information shared regarding the NCERT MCQ Questions for Class 11 Chemistry Chapter 12 Organic Chemistry: Some Basic Principles and Techniques with Answers Pdf free download is true and genuine as far as our knowledge is concerned. If you feel any information regarding CBSE Class 11 Chemistry Organic Chemistry: Some Basic Principles and Techniques MCQs Multiple Choice Questions with Answers is missing do reach us and we will look into it and add it accordingly.

error: Content is protected !!