Advertisement Remove all ads

Chemistry Shaalaa.com Model Set 2 2020-2021 HSC Science (General) 12th Board Exam Question Paper Solution

Advertisement Remove all ads
Chemistry [Shaalaa.com Model Set 2]
Marks: 70Academic Year: 2020-2021
Date: April 2021
Duration: 3h
  1. The question paper is divided into four sections.
  2. Section A: Q. No. 1 contains Ten multiple-choice type of questions carrying One mark each.
  3. Section A: Q. No. 2 contains Eight very short answer type of questions carrying One mark each.
  4. Section B: Q. No. 3 to Q. No. 14 contains Twelve short answer type of questions carrying Two marks each. (Attempt any Eight).
  5. Section C: Q. No.15 to Q. No. 26 contains Twelve short answer type of questions carrying Three marks each. (Attempt any Eight).
  6. Section D: Q.No. 27 to Q. No. 31 contains Five long answer type of questions carrying Four marks each. (Attempt any Three).
  7. Use of log table is allowed. Use of calculator is not allowed.
  8. Figures to the right indicate full marks.
  9. For each MCQ, correct answer must be written along with its alphabet.
    e.g., (a) ..... / (b ) .... / ( c ) .... / ( d) ..... Only first attempt will be considered for evaluation.
  10. Draw well labeled diagrams and write balanced equations wherever necessary.
  11. Given data:
    Atomic mass of C = 12, H = 1, O = 16
    Atomic number (Z): Mn = 25, Fe = 26, Ce = 58, Ar = 18,
    R = 8.314 J K-1 mol-1 or 0.083 L bar K-1 mol-1

Section A
[10]1 | Select and write the correct answer:
[1]1.i

Dacron is a copolymer of ethylene glycol and _______________

adipic acid

hexamethylenediamine

phthalic acid

terephthalic acid

Concept: Molecular Mass and Degree of Polymerization of Polymers
Chapter: [0.15] Introduction to Polymer Chemistry
[1]1.ii

In which of the following structure of DNA carries genetic information of the organism?

the primary structure of DNA

the double helix structure of DNA

complementary base pairing

sugar-phosphate backbone

Concept: Nucleic Acids
Chapter: [0.14] Biomolecules
[1]1.iii

The rate law relates to the rate of a chemical reaction in terms of _______.

concentration of catalyst

temperature

potential energy

mol/L of reactants

Concept: Rate of Reaction and Reactant Concentration
Chapter: [0.06] Chemical Kinetics
[1]1.iv

The following will react faster by SN1 mechanism

1-chloropropane

2-chloropropane

2-chloro-2-methylpropane

chloroethane

Concept: Preparation, Properties and Uses of Propane-1, 2, 3 Triol - Chemical Properties
Chapter: [0.1] Halogen Derivatives
[1]1.v

The change in internal energy in a reaction when 2kJ of heat is released by the system and 6 kJ of work is done on the system will be ______.

+4 kJ

4kJ

+3 kJ

– 8 kJ

Concept: Internal Energy (U)
Chapter: [0.04] Chemical Thermodynamics
[1]1.vi

In interhalogen compounds, which of the following halogens is never the central atom?

I

Cl

Br

F

Concept: Chemical Properties of Elements of Groups 16, 17 and 18
Chapter: [0.07] Elements of Groups 16, 17 and 18
[1]1.vii

The catalyst used for decomposition of KClO3 is _______.

ZnO

MnO2

CuO

K2O

Concept: Trends in Atomic Properties of the First Transition Series
Chapter: [0.08] Transition and Inner Transition Elements
[1]1.viii

The following ion has the maximum number of unpaired electrons.

Sc3+

Ti3+

Fe3+

Co2+

Concept: Oxidation States of First Transition Series
Chapter: [0.08] Transition and Inner Transition Elements
[1]1.ix

The molar conductivity and conductivity of AgNO3 solution is 121.4 Ω–1 cm2 mol–1 and 2.428 × 10–3 Ω–1 cm–1 at 25 °C. What is molar concentration of AgNO3 solution?

0.2 M

0.02 M

2.0 M

2.2 M

Concept: Electrical Conductance of Solution
Chapter: [0.05] Electrochemistry
[1]1.x

For a reaction \[\ce{HCl_{(aq)} + H2O_{(l)} ⇌ H3O^+_{ (aq)} + Cl^-_{ (aq)}}\]

Which of the following is a conjugate acid-base pair?

HCl and H2O

H3O+

H3O+ and H2O

HCl and H3O+

Concept: Acids and Bases
Chapter: [0.03] Ionic Equilibria
[8]2 | Answer the following:
[1]2.i

Which principle of green chemistry has its perspective towards carrying out reactions at room temperature and pressure?

Concept: Principles of Green Chemistry
Chapter: [0.16] Green Chemistry and Nanochemistry
[1]2.ii

Write the name of the catalyst used for preparation of high density polythene polymer.

Concept: Polymers - Some Important Polymers
Chapter: [0.15] Polymers [0.15] Introduction to Polymer Chemistry
[1]2.iii

Write the order of reactivity of alkyl halides with ammonia.

Concept: Amines - Preparation of Amines
Chapter: [0.13] Amines [13.01] Amines
[1]2.iv

Give SI unit of resistivity.

Concept: Electrical Conductance of Solution
Chapter: [0.05] Electrochemistry
[1]2.v

Give SI unit of resistivity.

Concept: Electrical Conductance of Solution
Chapter: [0.05] Electrochemistry
Advertisement Remove all ads
[1]2.vi

What is lanthanoid contraction?

Concept: Applications of Lanthanoids
Chapter: [0.08] Transition and Inner Transition Elements
[1]2.vii

Write the name of the product when ketones react with 1,2-diol in presence of dry HCl.

Concept: Chemical Properties of Aldehydes and Ketones
Chapter: [0.12] Aldehydes, Ketones and Carboxylic Acids
[1]2.viii

Complete the following reaction.

\[\ce{H2N - CH2 - COOH + H2N - CH2 - CH2 - COOH ->[-H2O] ?}\]

Concept: Proteins
Chapter: [0.14] Biomolecules
Section B
[2]3 | Attempt any Eight:

Write industrial application of enzyme catalysis.

Concept: Proteins
Chapter: [0.14] Biomolecules
[2]4

For a very dilute solution, the osmotic pressure is given by π = n2RT/V where V is the volume in L containing n2 moles of nonvolatile solute. Establish the equation for molar mass of solute.

Concept: Vapour Pressure Lowering
Chapter: [0.02] Solutions
[2]5

Define molar solubility. Write it’s unit.

Concept: Solubility Product and Its Applications - Solubility product
Chapter: [0.03] Ionic Equilibria
[2]6

Distinguish between : Order and Molecularity of reaction

Concept: Temperature Dependence of Reaction Rates
Chapter: [0.06] Chemical Kinetics
[2]7

What is the action of following reagents on pent-3-enal?

  1. H2/Ni
  2. LiAlH4/H3O+
Concept: Alcohols and Phenols
Chapter: [0.11] Alcohols, Phenols and Ethers
[2]8

How many moles of electrons are required for reduction of 2 moles of Zn2+ to Zn?

Concept: Electrochemical Cells
Chapter: [0.04] Electrochemistry [0.05] Electrochemistry
[2]9

Explain. Aryl halides are less reactive than alkyl halides towards nucleophilic substitution reactions.

Concept: Preparation, Properties and Uses of Propane-1, 2, 3 Triol - Chemical Properties
Chapter: [0.1] Halogen Derivatives
[2]10

Write four points of distinction between Lanthanoids and Actinoids.

Concept: F-block Elements - The Actinoids
Chapter: [0.08] Transition and Inner Transition Elements [8.02] F-block Elements
[2]11

Write Classification of aliphatic ketones with suitable example

Concept: Classification of Aldehydes, Ketones and Carboxylic Acids
Chapter: [0.12] Aldehydes, Ketones and Carboxylic Acids
[2]12

Describe Cannizzaro reaction

Concept: Aldehydes and Ketones - Chemical Reactions of Aldehydes and Ketones - Reactions Due to A-hydrogen
Chapter: [0.12] Aldehydes, Ketones and Carboxylic Acids
[2]13

write the structure of the monomer used in natural rubber.

Concept: Polymers - Some Important Polymers
Chapter: [0.15] Polymers [0.15] Introduction to Polymer Chemistry
[2]14

Calculate the number of unit cells in 0.3 g of a species having density of 8.5 g/cm3 and unit cell edge length 3.25 × 10-8 cm.

Concept: Cubic System
Chapter: [0.01] Solid State
Section C
[3]15 | Attempt any Eight:

Explain any three characteristic features of nanoparticles.

Concept: Nanoparticles and Nanotechnology
Chapter: [0.16] Green Chemistry and Nanochemistry
[3]16

Explain Hoffmann’s exhaustive alkylation with suitable reactions.

Concept: Amines - Preparation of Amines
Chapter: [0.13] Amines [13.01] Amines
Advertisement Remove all ads
[3]17

Define buffer solution.

Concept: Ionic Equilibria - Buffer Solutions
Chapter: [0.03] Ionic Equilibria

Explain the types of buffer solutions.

Concept: Ionic Equilibria - Buffer Solutions
Chapter: [0.03] Ionic Equilibria
[3]18

Why is molecularity applicable for only elementary reactions whereas order of a reaction is applicable for elementary and complex reactions? Explain with suitable examples.

Concept: Molecularity of Elementary Reactions
Chapter: [0.06] Chemical Kinetics
[3]19

State Kohlrausch law of independent migration of ions.

Concept: Electrical Conductance of Solution
Chapter: [0.05] Electrochemistry
[3]20

Define coordination number.

Concept: Terms Used in Coordination Chemistry
Chapter: [0.09] Coordination Compounds

Define Anionic sphere complex.

Concept: Terms Used in Coordination Chemistry
Chapter: [0.09] Coordination Compounds

Draw optical isomers of [Co(en)3]3+.

Concept: Isomerism in Coordination Compounds
Chapter: [0.09] Coordination Compounds
[3]21

What is Grignard reagent? How is it prepared? Why are they prepared under anhydrous condition?

Concept: Methods of Preparation of Alkyl Halides
Chapter: [0.1] Halogen Derivatives
[3]22

Derive the expression for work done in chemical reaction. Write the relationship between ∆H and ∆U for an isochoric process.

Concept: Chemical Thermodynamics
Chapter: [0.04] Chemical Thermodynamics
[3]23

Write three uses of sulfuric acid.

Concept: Oxoacids
Chapter: [0.07] Elements of Groups 16, 17 and 18
[3]24

Discuss the position of d-block elements, lanthanoids and actinoids in the periodic table.

Concept: Common Properties of d Block Elements
Chapter: [0.08] Transition and Inner Transition Elements
[3]25

Discuss the position of d-block elements, lanthanoids and actinoids in the periodic table.

Concept: Common Properties of d Block Elements
Chapter: [0.08] Transition and Inner Transition Elements
[3]26

The unit cell of Na is bcc and its density is 0.97 g/cm3. What is the radius of a sodium atom if the molar mass of Na is 23 g/mol?

Concept: Crystal Structure
Chapter: [0.01] Solid State
Section D
[4]27 | Attempt any Three:
[2]27.i

Explain the fact that in alkyl aryl ethers, the alkoxy group is ring activating and ortho/para directing towards electrophilic aromatic substitution.

Concept: Ethers
Chapter: [0.11] Alcohols, Phenols and Ethers
[2]27.ii

An organic compound gives hydrogen on reaction with sodium metal. It forms an aldehyde with molecular formula C2H4O on oxidation with pyridinium chlorochromate. Give the chemical equations in support of these observations.

Concept: Alcohols and Phenols
Chapter: [0.11] Alcohols, Phenols and Ethers
[4]28

Calculate the standard enthalpy of formation of liquid methanol from the following data:

  1. \[\ce{CH3OH_{(l)} + \frac{3}{2} O_{2(g)} -> CO_{2(g)} + 2H2O_{(l)}}\]     ∆H° = – 726 kJ mol–1
  2. \[\ce{C_{(Graphite)} + O_{2(g)} -> CO_{2(g)}}\]          ∆cH° = – 393 kJ mol–1
  3. \[\ce{H_{2(g)} + \frac{1}{2} O_{2(g)} -> H2O_{(l)}}\]          ∆fH° = – 286 kJ mol–1 
Concept: Thermochemistry
Chapter: [0.04] Chemical Thermodynamics
[4]29

Describe the manufacturing of H2SO4 by the contact process.

Concept: Chemical Properties of Elements of Groups 16, 17 and 18
Chapter: [0.07] Elements of Groups 16, 17 and 18
[4]30

Explain, why [Co(NH3)6]3+ ion is low spin? Calculate number of unpaired electrons and write the geometry of [Co(NH3)6]3+.

Concept: Theories of Bonding in Complexes
Chapter: [0.09] Coordination Compounds
[4]31

Explain with vapour pressure-temperature curves that the freezing point of a solvent is lowered by dissolving a nonvolatile solute into it. Give reason for such lowering of freezing of solvent.

Concept: Relative Molecular Mass of Non-volatile Substances - Depression in Freezing Point
Chapter: [0.02] Solutions
Advertisement Remove all ads
Advertisement Remove all ads

Request Question Paper

If you dont find a question paper, kindly write to us





      View All Requests

Submit Question Paper

Help us maintain new question papers on Shaalaa.com, so we can continue to help students




only jpg, png and pdf files

Maharashtra State Board previous year question papers 12th Board Exam Chemistry with solutions 2020 - 2021

     Maharashtra State Board 12th Board Exam Chemistry question paper solution is key to score more marks in final exams. Students who have used our past year paper solution have significantly improved in speed and boosted their confidence to solve any question in the examination. Our Maharashtra State Board 12th Board Exam Chemistry question paper 2021 serve as a catalyst to prepare for your Chemistry board examination.
     Previous year Question paper for Maharashtra State Board 12th Board Exam Chemistry-2021 is solved by experts. Solved question papers gives you the chance to check yourself after your mock test.
     By referring the question paper Solutions for Chemistry, you can scale your preparation level and work on your weak areas. It will also help the candidates in developing the time-management skills. Practice makes perfect, and there is no better way to practice than to attempt previous year question paper solutions of Maharashtra State Board 12th Board Exam.

How Maharashtra State Board 12th Board Exam Question Paper solutions Help Students ?
• Question paper solutions for Chemistry will helps students to prepare for exam.
• Question paper with answer will boost students confidence in exam time and also give you an idea About the important questions and topics to be prepared for the board exam.
• For finding solution of question papers no need to refer so multiple sources like textbook or guides.
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×