Share

Books Shortlist

# Question Paper Solutions for Chemistry Delhi Set 3 2015-2016 CBSE (Science) Class 12

SubjectChemistry
Year2015 - 2016 (March)
Chemistry
Delhi Set 3
2015-2016 March
Marks: 70

[1]1

What type of magnetism is shown by a substance if magnetic moments of domains are arranged in same direction?

Chapter: [1] Solid State
Concept: Magnetic Properties
[1]2

Out of , which is more reactive towards SN1 reaction and why?

Chapter: [10] Haloalkanes and Haloarenes
Concept: Chemical Reactions of Haloalkanes and Haloarenes - Reactions of Haloalkanes - Nucleophilic Substitution Reactions
[1]3

On adding NaOH to ammonium sulphate, a colourless gas with pungent odour is evolved, which forms a blue-coloured complex with Cu2+ ion. Identify the gas.

Chapter: [9] Coordination Compounds
Concept: Bonding in Coordination Compounds - Colour in Coordination Compounds
[1]4

What is the reason for the stability of colloidal sols?

Chapter: [5] Surface Chemistry
Concept: Properties of Colloidal Solutions
[1]5

Write the IUPAC name of the given compound:

Chapter: [9] Coordination Compounds
Concept: Nomenclature of Coordination Compounds - Naming of Mononuclear Coordination Compounds
[2]6

When a co-ordination compound CrCl3.6H2O is mixed with AgNO3, 2 moles of AgCl are precipitated per mole of the compound. Write

(i) Structural formula of the complex.

(ii) IUPAC name of the complex.

Chapter: [9] Coordination Compounds
Concept: Nomenclature of Coordination Compounds - Naming of Mononuclear Coordination Compounds
[2]7

From the given cells:

Lead storage cell, Mercury cell, Fuel cell and Dry cell

(i) Which cell is used in hearing aids?

(ii) Which cell was used in Apollo Space Programme?

(iii) Which cell is used in automobiles and inverters?

(iv) Which cell does not have long life?

Chapter: [3] Electrochemistry
Concept: Batteries - Primary Batteries
[2]8 | Attempt any ONE
[1]8.1

When chromite ore FeCr2O4 is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).

(i) Write the formulae of the compounds (A), (B) and C.

(ii) Write one use of compound (C).

Chapter: [8] "D" and "F" Block Elements
Concept: Some Important Compounds of Transition Elements - Oxides and Oxoanions of Metals
[1]8.2

Complete the following chemical equation

8MnO4- + 3S2O32- + H2O →

Chapter: [8] "D" and "F" Block Elements
Concept: Some Important Compounds of Transition Elements - Oxides and Oxoanions of Metals

Complete the following chemical equation

Cr2O72- + 3Sn2+ + 14H+

Chapter: [8] "D" and "F" Block Elements
Concept: Some Important Compounds of Transition Elements - Oxides and Oxoanions of Metals
[2]9

Write the mechanism of the following reaction:

Chapter: [11] Alcohols, Phenols and Ethers
Concept: Chemical Reactions of Alcohols and Phenols - Reactions Involving Cleavage of Carbon–Oxygen (C–O) Bond in Alcohols
[2]10

For a reaction :

(i) Write the order and molecularity of this reaction.

(ii) Write the unit of k.

Chapter: [4] Chemical Kinetics
Concept: Factors Influencing Rate of a Reaction
[3]11

The rate constant for the first-order decomposition of H2O2 is given by the following equation:

logk=14.2-(1.0xx10^4)/TK

Calculate Ea for this reaction and rate constant k if its half-life period be 200 minutes.

(Given: R = 8.314 JK–1 mol–1)

Chapter: [4] Chemical Kinetics
Concept: Temperature Dependence of the Rate of a Reaction
[3]12
[1]12.1

Chapter: [5] Surface Chemistry
[1]12.2

Out of MgCl2 and AlCl3, which one is more effective in causing coagulation of negatively charged sol and why?

Chapter: [5] Surface Chemistry
Concept: Properties of Colloidal Solutions
[1]12.3

Out of sulphur sol and proteins, which one form multimolecular colloids?

Chapter: [5] Surface Chemistry
Concept: Classification of Colloids - Classification Based on Nature of Interaction Between Dispersed Phase and Dispersion Medium
[3]13 | Given reasons
[1]13.1

The dipole moment of chlorobenzene is lower than that of cyclohexyl chloride

Chapter: [10] Haloalkanes and Haloarenes
Concept: Chemical Reactions of Haloalkanes and Haloarenes - Reactions of Haloalkanes - Nucleophilic Substitution Reactions
[1]13.2

C–Cl bond length in chlorobenzene is shorter than C–Cl bond length in CH3–Cl.

Chapter: [10] Haloalkanes and Haloarenes
Concept: Chemical Reactions of Haloalkanes and Haloarenes - Reactions of Haloalkanes - Nucleophilic Substitution Reactions
[1]13.3

SN1 reactions are accompanied by racemization in optically active alkyl halides.

Chapter: [10] Haloalkanes and Haloarenes
Concept: Chemical Reactions of Haloalkanes and Haloarenes - Reactions of Haloalkanes - Nucleophilic Substitution Reactions
[3]14

An element crystallizes in a f.c.c. lattice with cell edge of 250 pm. Calculate the density if 300 g of this element contain 2 × 1024 atoms.

Chapter: [1] Solid State
Concept: Calculations Involving Unit Cell Dimensions
[3]15
[1]15.1

Account for the following:

Mn shows the highest oxidation state of +7 with oxygen but with fluorine, it shows oxidation state of +4.

Chapter: [8] "D" and "F" Block Elements
Concept: General Properties of the Transition Elements (D-block)
[1]15.2

Give reasons: Transition metals show variable oxidation states.

Chapter: [8] "D" and "F" Block Elements
Concept: General Properties of the Transition Elements (D-block)
[1]15.3

Give reasons: Actinoids show irregularities in their electronic configurations.

Chapter: [8] "D" and "F" Block Elements
Concept: F-block Elements - The Actinoids
[3]16
[1]16.1

Write the main product(s) in each of the following reactions:

Chapter: [11] Alcohols, Phenols and Ethers
Concept: Chemical Reaction of Ethers - Cleavege of C-O Bonds
[1]16.2

Write the main product(s) in each of the following reactions:

Chapter: [11] Alcohols, Phenols and Ethers
Concept: Preparation of Alcohols from Alkenes, Carbonyl Compounds and Grignard Reagents
[1]16.3

Write the main product(s) in each of the following reactions:

Chapter: [11] Alcohols, Phenols and Ethers
Concept: Chemical Reactions of Phenols (Only)
[3]17
[1]17.1

Name the method of refining of metals such as Germanium.

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: Refining
[1]17.2

In the extraction of Al, impure Al2O3 is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: Occurrence of Metals
[1]17.3

What is the role of coke in the extraction of iron from its oxides?

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: Occurrence of Metals
[3]18

Calculate e.m.f of the following cell at 298 K:

2Cr(s) + 3Fe2+ (0.1M) → 2Cr3+ (0.01M) + 3 Fe(s)

Given: E°(Cr3+ | Cr) = – 0.74 VE° (Fe2+ | Fe) = – 0.44 V

Chapter: [3] Electrochemistry
Concept: Galvanic Cells - Introduction
[3]19
[1]19.1

Write the name of two monosaccharides obtained on hydrolysis of lactose sugar.

Chapter: [14] Biomolecules
Concept: Carbohydrates - Monosaccahrides
[1]19.2

Why Vitamin C cannot be stored in our body ?

Chapter: [14] Biomolecules
Concept: Vitamins - Classification of Vitamins
[1]19.3

What is the difference between a nucleoside and nucleotide ?

Chapter: [14] Biomolecules
Concept: Nucleic Acids - Structure of Nucleic Acids
[3]20

For the complex [Fe(CN)6]3–, write the hybridization type, magnetic character and spin nature of the complex. (At. number : Fe = 26).

Chapter: [9] Coordination Compounds
Concept: Bonding in Coordination Compounds - Magnetic Properties of Coordination Compounds

Draw one of the geometrical isomers of the complex [Pt(en)2Cl2]2+ which is optically active.

Chapter: [9] Coordination Compounds
Concept: Isomerism in Coordination Compounds - Stereoisomerism
[3]21

Write the structures of A, B and C in the following:

Chapter: [13] Organic Compounds Containing Nitrogen
Concept: Diazonium Salts - Chemical Reaction of Diazonium Salts - Reactions Involving Displacement of Nitrogen

Write the structures of A, B and C in the following:

Chapter: [10] Haloalkanes and Haloarenes
Concept: Chemical Reactions of Haloalkanes and Haloarenes - Reactions of Haloalkanes - Nucleophilic Substitution Reactions
[3]22 | Attempt any ONE
[3]22.1
[1]22.1.1

What is the role of t-butyl peroxide in the polymerization of ethene?

Chapter: [15] Polymers
Concept: Types of Polymerisation Reactions - Addition Polymerisation Or Chain Growth Polymerisation
[1]22.1.2

Identify the monomers in the following polymer:

Chapter: [15] Polymers
Concept: Introduction of Polymers
[1]22.1.3

Arrange the following polymers in the increasing order of their intermolecular forces:

Polystyrene, Terylene, Buna-S

Chapter: [15] Polymers
Concept: Introduction of Polymers
[3]22.2

Write the mechanism of free radical polymerization of ethene.

Chapter: [15] Polymers
Concept: Types of Polymerisation Reactions - Addition Polymerisation Or Chain Growth Polymerisation
[4]23

Due to hectic and busy schedule, Mr Angad made his life full of tensions and anxiety. He started taking sleeping pills to overcome the depression without consulting the doctor. Mr Deepak, a close friend of Mr. Angad advised him to stop taking sleeping pills and suggested to change his life lifestyle by doing yoga, meditation and some physical exercise. Mr. Angad followed his friend’s advice and after few days he started feeling better.

(i) What are the values (at least two) displayed by Mr. Deepak?

(ii) Why is it not advisable to take sleeping pills without consulting doctor?

(iii) What are tranquilisers? Give two examples.

Chapter: [16] Chemistry in Everyday Life
Concept: Drugs and Their Classification
[5]24 | Attempt any ONE
[5]24.1

Write the structures of A, B, C, D and E in the following reactions:

Chapter: [11] Alcohols, Phenols and Ethers
Concept: Chemical Reactions of Phenols (Only)
[5]24.2
[1]24.2.1

Write the chemical equation for the reaction involved in Cannizzaro reaction.

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Aldehydes and Ketones - Chemical Reactions of Aldehydes and Ketones - Other Reactions
[1]24.2.2

Draw the structure of the semicarbazone of ethanal.

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Aldehydes and Ketones - Chemical Reactions of Aldehydes and Ketones - Nucleophilic Addition Reactions
[1]24.2.3

Why pKa of F-CH2-COOH is lower than that of Cl−CH2−COOH?

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Carboxylic Acids - Chemical Reactions of Carboxylic Acids - Reactions Involving Cleavege of O-H Bond
[1]24.2.4

Write the product in the following reaction:

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Aldehydes and Ketones - Preparation of Aldehydes
[1]24.2.5

How can you distinguish between propanal and propanone?

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Introduction of Aldehydes, Ketones and Carboxylic Acids
[5]25 | Attempt any ONE
[5]25.1
[3]25.1.1

Calculate the freezing point of solution when 1.9 g of MgCl2 (M = 95 g mol−1) was dissolved in 50 g of water, assuming MgCl2 undergoes complete ionization.

(Kf for water = 1.86 K kg mol−1)

Chapter: [2] Solutions
Concept: Colligative Properties and Determination of Molar Mass - Depression of Freezing Point
[2]25.1.2

Out of 1 M glucose and 2 M glucose, which one has a higher boiling point and why?

Chapter: [2] Solutions
Concept: Colligative Properties and Determination of Molar Mass - Elevation of Boiling Point

What happens when the external pressure applied becomes more than the osmotic pressure of solution?

Chapter: [2] Solutions
Concept: Colligative Properties and Determination of Molar Mass - Osmosis and Osmotic Pressure
[5]25.2
[3]25.2.1

When 2.56 g of sulphur was dissolved in 100 g of CS2, the freezing point lowered by 0.383 K. Calculate the formula of sulphur (Sx).

(Kf for CS2 = 3.83 K kg mol−1, Atomic mass of sulphur = 32 g mol−1]

Chapter: [2] Solutions
Concept: Colligative Properties and Determination of Molar Mass - Depression of Freezing Point
[2]25.2.2

Blood cells are isotonic with 0.9% sodium chloride solution. What happens if we place blood cells in a solution containing

(i) 1.2% sodium chloride solution?

(ii) 0.4% sodium chloride solution?

Chapter: [2] Solutions
Concept: Colligative Properties and Determination of Molar Mass - Osmosis and Osmotic Pressure
[5]26 | Attempt any ONE
[5]26.1
[3]26.1.1
[1]26.1.1.1

Account for the following :

Ozone is thermodynamically unstable.

Chapter: [7] P - Block Elements
Concept: P - Block Group 16 Elements - Ozone
[1]26.1.1.2

Account for the following : Solid PCl5 is ionic in nature.

Chapter: [7] P - Block Elements
Concept: P - Block Group 15 Elements - Phosphorus Halides
[1]26.1.1.3

Account for the following :

Fluorine forms only one oxoacid HOF

Chapter: [7] P - Block Elements
Concept: P - Block Group 17 Elements - Oxoacids of Halogens
[2]26.1.2
[1]26.1.2.1

Draw the structure of BrF5

Chapter: [7] P - Block Elements
Concept: P - Block Group 17 Elements - Interhalogen Compounds
[1]26.1.2.2

Draw the structures of the following molecules: XeF4

Chapter: [7] P - Block Elements
Concept: P - Block Group 18 Elements - Concept of Group 18 Elements
[5]26.2
[1]26.2.1

Compare the oxidizing action of F2 and Cl2 by considering parameters such as bond dissociation enthalpy, electron gain enthalpy and hydration enthalpy.

Chapter: [7] P - Block Elements
Concept: P - Block Group 17 Elements - Concept of Group 17 Elements
[2]26.2.2

Write the conditions to maximize the yield of H2SO4 by contact process.

Chapter: [7] P - Block Elements
Concept: P - Block Group 16 Elements - Sulphuric Acid
[2]26.2.3

Arrange the following in the increasing order of property mentioned :

H3PO3, H3PO4, H3PO2 (Reducing character)

Chapter: [7] P - Block Elements
Concept: Concept of Group 15 Elements

Arrange the following in the increasing order of property mentioned :

NH3, PH3, AsH3, SbH3, BiH3 (Base strength)

Chapter: [7] P - Block Elements
Concept: Concept of Group 15 Elements

#### 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

## CBSE previous year question papers Class 12 Chemistry with solutions 2015 - 2016

CBSE Class 12 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 CBSE Class 12 Chemistry question paper 2016 serve as a catalyst to prepare for your Chemistry board examination.
Previous year Question paper for CBSE Class 12 Chemistry-2016 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 CBSE Class 12.

How CBSE Class 12 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.
S