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Question Paper Solutions - Chemistry 2012 - 2013-H.S.C-12th Board Exam Maharashtra State Board (MSBSHSE)


Marks: 70
[7]1 | Select and write the most appropriate answer from the given alternatives for each sub-question:
[1]1.1

In body centred cubic structure the space occupied is about

(A) 68%                                                     (B) 53%

(C) 38%                                                     (D) 32%

Chapter: [1] Solid State
Concept: Packing Efficiency - Efficiency of Packing in Body-centred Cubic Structures
[1]1.2

For a gaseous reaction the unit of rate of reaction is

(A) L atm s-1

(B) atm mol-1 s-1

(C) atm s1

(D) mol s

Chapter: [4] Chemical Kinetics
Concept: Rate of a Chemical Reaction
[1]1.3

Which of the following compounds contain S = O as well as S = S bonds?

(A) Sulphuric acid

(B) Thiosulphuric acid

(C) Sulphurous acid

(D) Thiosulphurous acid

 

Chapter: [8] Chemistry of p-Block Elements: Group 16, 17, 18
Concept: P - Block Group 16 Elements - Compounds of Sulphur
[1]1.4

Which of the following solutions shows maximum depression in freezing point?

(A) 0.5 M Li2SQ4

(B) 1 M NaCl

(C) 0.5 M A12(SO4)3

(D) 0.5 MBaC12

Chapter: [2] Solutions and Colligative Properties
Concept: Colligative Properties and Determination of Molar Mass - Depression of Freezing Point
[1]1.5

For a chemical reaction ΔS=0.035 kJ/k and ΔH=20kJ.

(A) 5.14 K

(B) 57.14 K

(C) 571.4 K

(D) 5714.0 K

Chapter: [3] Chemical Thermodynamics and Energetic
Concept: Chemical Thermodynamics and Energetic - Internal Energy and Enthalpy
[1]1.6

The standard e.m.f of the following cell is 0.463 V

`Cu|Cu_(1m)^(++)`

What is the standard potential of Cu electrode?

(A) 1.137 V

(B) 0.337 V

(C) 0.463 V

(D) - 0.463 V

Chapter: [4] Electrochemistry
Concept: Galvanic Cells - Introduction
[1]1.7

Fe2O3 is reduced to spongy iron near the top of blast furance by

(A) H2

(B) CaO

(C) SiO2

(D) CO

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: Occurrence of Metals
[12]2 | (A) Answer any SIX of the following
[2]2.1

Distinguish between crystalline solid and amorphous solid

Chapter: [1] Solid State
Concept: Amorphous and Crystalline Solids
[2]2.2

State Kohlrausch Law

Chapter: [6.04] Electrolytic conductance
Concept: Conductance of Electrolytic Solutions - Variation of Conductivity and Molar Conductivity with Concentration

Write mathematical expression of molar conductivity of the given solution at infinite dilution.

Chapter: [6.04] Electrolytic conductance
Concept: Conductance of Electrolytic Solutions - Variation of Conductivity and Molar Conductivity with Concentration
[2]2.3

Write cell reaction in lead storage battery during discharge.

Chapter: [4] Electrochemistry
Concept: Batteries - Primary Batteries
[2]2.4

Draw structure and write geometry of PCl3 and PCl5.

Chapter: [7.01] Group 15 Elements
Concept: P - Block Group 15 Elements - Compounds of Phosphorus
[2]2.5

Prove that ΔH=ΔU+ΔnRT. what is the condition under which ΔU=ΔH?

Chapter: [9] Kinetic Theory of Gases and Radiation
Concept: Chemical Thermodynamics and Energetic - First Law of Thermodynamics
[2]2.6

Mention names and formulae of two ores of alumunium.

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: Occurrence of Metals
[2]2.7

Derive the relationship between relative lowering of vapour pressure and molar mass of nonvolatile solute.

Chapter: [2] Solutions and Colligative Properties
Concept: Colligative Properties and Determination of Molar Mass - Relative Lowering of Vapour Pressure
[2]2.8

What is pseudo first order reaction? Give one· example of it.

Chapter: [5] Chemical Kinetics
Concept: Factors Influencing Rate of a Reaction
[9]3 | Answer any THREE of the following:
[3]3.1

Calculate the mole fraction and molality of HNO3 in solution contaning 12.2%HNO3 (Given atomic mases:H=1, N=13,O=16)

Chapter: [2] Solutions and Colligative Properties
Concept: Colligative Properties and Determination of Molar Mass - Introduction
[3]3.2
 

Consider the reaction

`3I_((aq))^-) +S_2O_8^(2-)->I_(3(aq))^-) + 2S_2O_4^(2-)`

At particular time t, `(d[SO_4^(2-)])/dt=2.2xx10^(-2)"M/s"`

What are the values of the following at the same time?

a. `-(d[I^-])/dt`

b. `-(d[S_2O_8^(2-)])/dt`

c. `-(d[I_3^-])/dt`

 

 
Chapter: [4] Chemical Kinetics
Concept: Temperature Dependence of the Rate of a Reaction
[3]3.3

300 M mol of perfect gas occupies 13 L at 320 K. Calculate the work done in joules when the gas expands-

(a) isothermally against a Constant external pressure of 0.20atm.

(b) isothermal and reversible process.

(c) into vaccum until the volume of gas is increased by 3L (R=8.314J mol-1 K-1)

Chapter: [3] Chemical Thermodynamics and Energetic
Concept: Chemical Thermodynamics and Energetic - Work, Heat, Energy, Extensive and Intensive Properties
[3]3.4

What is the action of Excess of air on ammonia?

Chapter: [7.01] Group 15 Elements
Concept: P - Block Group 15 Elements - Ammonia

What is the action of Excess of chlorine on ammonia?

 

 

Chapter: [7.01] Group 15 Elements
Concept: P - Block Group 15 Elements - Ammonia

What is the action of Na Metal on ammonia? 

Chapter: [7.01] Group 15 Elements
Concept: P - Block Group 15 Elements - Ammonia
[7]4 | Answer any one of the following
[7]4.1
[2]4.1.1 | Explain with reason sign conventions of ΔS in the following reactions:
[1]4.1.1.1

Explain with reason sign conventions of ΔS in the following reaction

N2(g)+3H2(g)→2NH3(g)

Chapter: [1] Solid State
Concept: Number of Atoms in a Unit Cell
[1]4.1.1.2

Explain with reason sign conventions of ΔS in the following reaction

CO2(g) → CO2(g)

Chapter: [1] Solid State
Concept: Number of Atoms in a Unit Cell
[2]4.1.2 | Explain the following terms
[1]4.1.2.1

Explain the following term

Smelting

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: General Principles and Processes of Isolation of Elements - Principles and Methods of Extraction - Concentration
[1]4.1.2.2

Explain the following term

Flux

Chapter: [6] General Principles and Processes of Isolation of Elements
Concept: General Principles and Processes of Isolation of Elements - Principles and Methods of Extraction - Concentration
[3]4.1.3

Gold occurs as face centred cube and has a density of 19.30 kg dm-3. Calculate atomic radius of gold (Molar mass of Au=197)

Chapter: [1] Solid State
Concept: Number of Atoms in a Unit Cell
[7]4.2

a. Explain the trends in the following properties with reference to group 16:

1 Atomic radii and ionic radii

2 Density

3 ionisation enthalpy

4 Electronegativity

b. In the electolysis of AgNO3 solution 0.7g of Ag is deposited after a certain period of time. Calulate the quantity of electricity required in coulomb. (Molar mass of Ag is 107.9g mol-1)

 

Chapter: [7.02] Group 16 Elements
Concept: Concept of Group 16 Elements

Define Osmosis

Chapter: [7.02] Group 16 Elements
Concept: Concept of Group 16 Elements
[7]5 | Select and write the most appropriate answer from the given alternatives for each sub-question:
[1]5.1

ln which pair highest oxidation states of transition metals are found:

(A) nitriles and chlorides

(B) fluorides and chlorides

(C) fluorides and oxides

(D) nitriles and oxides

Chapter: [10] Chemistry of Transition and Inner-Transition Elements: d-Block: 3d, 4d and 5d series f-Block: 4f and 5f series
Concept: General Properties of the Transition Elements (D-block)
[1]5.2

which of the following carbocations is least stable?

(A) 

(B)

(C)

(D)

 

 

Chapter: [10.01] Haloalkanes
Concept: Haloalkanes and Haloarenes - Nature of C-x Bond
[1]5.3

Compound having general formula is called

(A) diester

(B) acid anhydride

(C) hemiacetal

(D) acetal

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Aldehydes and Ketones - Nomenclature
[1]5.4
 

The complex ion `[Co(H_2O)_5 (ONO)]^(2+) `

(A) linkage isomer

(B) ionisation isomer

(C) co-ordination isomer

(D) geometrical isomer

 
Chapter: [9] Coordination Compounds
Concept: Isomerism in Coordination Compounds - Structural Isomerism
[1]5.5

Inflammation af tongue is due to the deficiency of:

(A) Vitamin B1

(B) Vitamin B2

(C) Vitamin B5

(D) Vitamin B6

Chapter: [14.03] Vitamins
Concept: Vitamins - Important Vitamins, Their Sources and Their Deficiency Diseases
[1]5.6

Identify the compound 'B' in the following series of reaction:

(A) n-propyl chloride

(B) Propanamine

(C) n-propyl alcohol

(D) Isoproply alcohol

Chapter: [12.02] Methods of preparation, manufacture, properties and use
Concept: Alcohols - Methods of Preparation
[1]5.7

Which of the following reagents is best for the following conversion?

(A) LiAlH4

(B) 

(C) H2/Ni, 453 K

(D) Zn-Hg+HCl(con)

Chapter: [12.02] Methods of preparation, manufacture, properties and use
Concept: Alcohols - Methods of Preparation
[12]6 | Answer any SIX ofthe following
[2]6.1

Calculate magnetic moment of  `Fe_((aq))^(2+) ion (Z=26).`

Chapter: [10] Chemistry of Transition and Inner-Transition Elements: d-Block: 3d, 4d and 5d series f-Block: 4f and 5f series
Concept: General Properties of the Transition Elements (D-block)
[2]6.2

How is ethanol prepared from methanal by using Grignard reagent?

Chapter: [12.02] Methods of preparation, manufacture, properties and use
Concept: Alcohols - Methods of Preparation
[2]6.3

Write the chemical reaction to prepare novolac polymer.

Chapter: [15] Polymers
Concept: Polymers - Some Important Polymers
[2]6.4

Why does p-nitrochlorobenzene undergo displacement reactions readily with attack of nucleophilic HOΘ ion?

Chapter: [10.02] Haloarenes
Concept: Haloarenes - Nucleophilic Substitution
[2]6.5

What is the action of bromine in alkaline medium on

i. CH3CH2NO2

ii. 

Chapter: [10] Haloalkanes and Haloarenes
Concept: Methods of Preparation of Haloalkanes and Haloarenes
[2]6.6

Define antioxidants?

Chapter: [16.02] Chemicals in Food
Concept: Chemicals in Food - Artificial Sweetening Agents and Food Preservatives
[2]6.7

How is 4-methylpent-3-en-2-one obtained from propan-2-one?

Chapter: [12.01] Aldehydes and Ketones
Concept: Aldehydes and Ketones - Reactivity of Alpha Hydrogen in Aldehydes
[2]6.8

What are hormones?

Chapter: [14.02] Proteins
Concept: Proteins - Structure, Classification and Functions

Write the structure of simple triglycerides.

Chapter: [14.02] Proteins
Concept: Proteins - Structure, Classification and Functions
[9]7 | Answer any THREE of the following
[3]7.1

Write the different oxidation states of manganese.

Chapter: [8] "D" and "F" Block Elements
Concept: Electronic Configurations of the D-block Elements

Why +2 oxidation state of manganese is more stable?

Chapter: [10] Chemistry of Transition and Inner-Transition Elements: d-Block: 3d, 4d and 5d series f-Block: 4f and 5f series
Concept: General Properties of the Transition Elements (D-block)
[3]7.2

How are the following compounds prepared?

benzaldehyde from benzene

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

How are the following compounds prepared?

acetophenone from benzene

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

How are the following compounds prepared?

benzaldehyde from benzoyl chloride

Chapter: [12] Aldehydes, Ketones and Carboxylic Acids
Concept: Aldehydes and Ketones - Chemical Reactions of Aldehydes and Ketones - Nucleophilic Addition Reactions
[3]7.3

Write the structure of a nucleotide

Chapter: [14.04] Nucleic Acids
Concept: Introduction of Nucleic Acids

Write the structure of a nucleoside

Chapter: [14.04] Nucleic Acids
Concept: Introduction of Nucleic Acids

Define complex lipids

Chapter: [14.02] Proteins
Concept: Proteins - Structure, Classification and Functions
[3]7.4

Write the fomulae of the following compounds

Sodium hexanitrito- N - cobaltate (III)

Chapter: [9] Coordination Compounds
Concept: Nomenclature of Coordination Compounds - Formulas of Mononuclear Coordination Entities

Write the fomulae of the following compounds :

Tetraaquodichlorochromium (III) chloride

 

Chapter: [9] Coordination Compounds
Concept: Nomenclature of Coordination Compounds - Formulas of Mononuclear Coordination Entities

Write the fomulae of the following compounds

Potassium tetracyanoaurate (III) ion

Chapter: [9] Coordination Compounds
Concept: Nomenclature of Coordination Compounds - Formulas of Mononuclear Coordination Entities
[7]8 | Answer any ONE of the following
[7]8.1

Explain the following term: Homopolymers

Chapter: [15] Polymers
Concept: Polymers - Some Important Polymers

Explain the following term: Elastomers

Chapter: [15] Polymers
Concept: Introduction of Polymers

Explain the mechanism of cleansing action of soaps.

Chapter: [16] Chemistry in Everyday Life
Concept: Cleansing Agents - Soaps

Write balanced chemical equations for the action of phosphorous trichloride on propan-2-ol

Chapter: [15] Polymers
Concept: Introduction of Polymers

Write balanced chemical equations for the action of hydrogen bromide on styrene in the presence of a peroxide

Chapter: [16] Chemistry in Everyday Life
Concept: Cleansing Agents - Soaps

Write balanced chemical equations for the action of methyl bromide on silver propanoate

Chapter: [16] Chemistry in Everyday Life
Concept: Cleansing Agents - Soaps
[7]8.2

Write a short note on Hoffmann bromamide degradation.

Chapter: [15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
Concept: Amines - Preparation of Amines

Explain the mechanism of action of hydroiodic acid on 3-methylbutan-2-ol.

Chapter: [15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
Concept: Amines - Preparation of Amines

Mention 'two' uses of propan-2-one.

Chapter: [15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
Concept: Amines - Preparation of Amines
S