Solved question paper for Chemistry Sep-2021 (PSEB Class 12th)
Solved Question Paper
Chemistry Sep-2021
PSEB • Class 12th • 1st • Sep-2021
Chemistry previous year question papers on BRpaper help students looking for PSEB 12th Class Question Papers to browse Chemistry papers for board exam practice and revision. This subject section is useful for finding PSEB 12th Chemistry old question papers, PYQ-style papers, and related exam-preparation material where available, so students can study the question format, recurring topics, and marks pattern used in the Punjab board exam. If you are preparing for the Punjab School Education Board Class 12 Chemistry paper, this page can help you compare past question styles with sample paper and model paper trends, and focus on important questions more confidently. BRpaper is not the official website of Punjab School Education Board or any institution, and it does not publish official notices or academic updates.
Unit-I: Solid, State
Classification of solids based on different binding forces: molecular, ionic, covalent and metallic solids, amorphous and crystalline solids (elementary idea), unit cell in two dimensional and three dimensional lattices, calculation of density of unit cell, packing in solids packing efficiency, voids, number of atoms per unit cell in a cubic unit cell, points defects, electrical and magnetic properties. Band theory of metals, conductors, semiconductors and insulators and n and p type semiconductors.
Unit II: Solutions
Types of solutions, expression of concentration of solutions of solids in liquids, solubility of gases in liquids, solid solutions, colligative
properties - relative lowering of vapour pressure, Raoults Law, elevation of B.P., depression of freezing point, osmotic pressure, determination of molecular masses using colligative properties, abnormal molecular mass. Vant Hoff factor.
Unit III: Electrochemistry
Redox reactions; conductance in electrolytic solutions, specific and molar conductivity, variations of conductivity with concentration, Kohlrausch's Law, electrolysis and laws of electrolysis (elementary idea) dry cell-electrolytic cells and Galvanic cells; lead accumulator, EMF of a cell, standard electrode potential, Nernst equation and its application to chemical cells, fuel cells; corrosion. Relation between Gibbs Energy change and EMF of cell.
Unit IV: Chemical Kinetics
Rate of a reaction (average and instantaneous), factors affecting rates of reaction; concentration, temperature, catalyst; order and molecularity of a reaction: rate law and specific rate constant, integrated rate equations and' half life (only for zero and first order reactions); concept of collision theory (elementary idea, no mathematical treatment). Activation Energy, Arrhenious equation.
Unit V: Surface Chemistry
Absorption physiorption and chemisorption; factors affecting adsorption of gases on solids; catalysis; homogenous and heterogeneous,
activity and selectivity; enzyme catalysis; colloidal state: distinction between true solutions, colloids and suspensions; lyophillic, lyophobic, multimolecular and macromolecular/colloids; properties of colloids; Tyndall effect, Brownian movement, electrophoresis, coagulation; emulsion-types of emulsions.
Unit VI: General Principles and Processes of Isolation of Elements
Principles and methods of extraction – concentration, oxidation, reduction electrolytic method and refining; occurrence and principles of
extraction of aluminum, copper, zinc and Iron.
Unit VII: p-Block Element
Group 15 elements: General introduction, electronic configuration, occurrence, oxidation states, trends in physical and chemical
properties; nitrogen - preparation, properties and uses; compounds of nitrogen- preparation and properties of ammonia and nitric acids, oxides of nitrogen (structure only); Phosphorous-allotropic forms; compounds of phosphorous preparation and properties of phosphine, halides (PCl3,PCl5) and oxoacids (elementary idea only).
Group16 elements: General introduction, electronic configuration, oxidation states, occurrence, trends in physical and chemical
properties; dioxygen; preparation, properties and uses; classification of oxides; Ozone. Sulphur - allotropic forms; compounds of sulphur preparation, properties and uses of sulphur dioxide, sulphuric acid, industrial process of manufacture, properties and uses, oxoacids of sulphur (structures only).
Group 17 elements: (General introduction, electronic configuration, oxidation states, occurrence, trends in physical and chemical
properties; compounds of halogens; preparation, properties and uses of chlorine and hydrochloric acid, interhalogen compounds, oxoacids of halogens (structures only).
Group 18 elements: General introduction, electronic configuration. Occurrence, trends in physical and chemical properties, uses.
Unit-VIII: d and f Block Elements
General introduction, electronic configuration, occurrence and characteristics of transition metals, general trends in properties of the first
row transition metals-metallic character, ionization, enthalpy, oxidation states, ionic radii, colour, catalytic properties, magnetic properties, interstitial compounds, alloy formation. Preparation and properties of K2Cr2O7,and KMnO4. Lanthanoids - electronic configuration, oxidation states, chemical reactivity and lanthanoid contraction and consequences. Actenoids - Electronic configuration, oxidation states.
Unit-IX: Coordination Compounds
Coordination compounds - introduction, ligands, coordination number, colour, magnetic properties and shapes, IUPAC nomenclature of mononuclear coordination compounds, bonding; Werner’s theory VBT, CFT, Isomerism (structure and stereo) importance of coordination compounds (in qualitative analysis, extraction of metals and biological systems).
Unit-X: Haloalkanes and Haloarenes.
Haloalkanes: Nomenclature, nature of C-X bond, physical and chemical properties, mechanism of substitution reactions, optical rotation. Halearenes: Nature of C-X bond, substitution reactions (directive influence of halogen for monosubstituted compounds only) Uses and environmental effects of - dichloromethane, trichlromethane, tetrachloromethane, iodoform, freons, DDT.
Unit –XI: Alcohols, Phenols, and Ethers
Alcohols: Nomenclature, methods of preparation, physical and chemical properties (of primary alcohols only); identification of primary, secondary and tertiary alcohols; mechanism of dehydration, uses, with special reference to - methanol and ethanol. Phenols: Nomenclature, methods of preparation, physical and chemical properties, acidic nature of phenol, electrophilic substitution reactions, uses of phenols. Ethers: Nomenclature, methods of preparation, physical and chemical properties, uses.
Unit-XII: Aldehydes, Ketones aml Carboxylic Acids
Aldehydes and Ketones: Nomenclature, nature of carbonyl group, methods of preparation, physical and chemical properties, and mechanism of nucleophilic addition, reactivity of alpha hydrogen in aldehydes; uses. Carboxylic Acids: Nomenclature, acidic nature, methods of preparation, physical and chemical properties; uses.
Unit-XIII: Organic compounds containing Nitrogen
Amines: Nomenclature, classification, structure, methods of preparation, physical and chemical properties, uses, identification of primary,secondary and tertiary amines. Cyanides and Isocyanides - will be mentioned at relevant places in context. Dizonium Salts: Preparation, chemical reactions and importance in synthetic organic chemistry.
Unit-XIV: Biomolecules
Carbohydrates - Classification (aldoses and ketoses), monosaccaharides (glucose and fructose), oligosaccharides (sucrose, lactose, maltose), polysaccharides (starch, cellulose, glycogen); importance Proteins - Elementary idea of amino acids, peptide bond,polypeptides proteins, primary structure, secondary structure, tertiary structure and quaternary structure (qualitative idea only), denaturation of proteins; enzymes. Vitamins: Classification and functions. Harmones: Elementary idea (excluding structure) Nucleic Acids: DNA & RNA .
Unit-XV: Polymers
Classification - natural and synthetic, methods of polymerization (addition and condensation), copolymerization. Some important polymers; natural and synthetic like polythene, nylon, polyesters, bakelite, rubber. Biodegradable and Non- Biodegradable Polymers. Unit-XVI: Chemistry in everyday life :
1. Chemicals in medicines analgesic, transquilizers, antiseptics, disinfectants, antimicrobials, antifertility drugs, antibiotics, antacids,
antihistamines.
2. Chemicals in food- preservatives, artificial sweetening agents. Elementary idea of antioxidents.
3. Cleansing agents- soaps and detergents, cleansing action.
Solved Questions
Solved-
COMPREHENSION: Read the following passage and answer the questions1 to 5 given below
The adsorption is reversible, if the adsorbate can be easily removed from the surface of the adsorbent by physical
methods, if the adsorbate can not be removed from the surface of the adsorbent. It is called irreversible
adsorption.Examples of irreversible adsorption are adsorption of oxygen and adsorption of CO on tungsten surface
The substancesupon whose surface the change of concentration occurs, is called absorbent. The substance taken up
on the surface iscalled adsorbate. The common surface between the two phases where the adsorbed molecules
concentrate is called theinterface. Physical adsorption occurs when the adsorbate gas molecules are held by physical
forces like Van der Waalsforces. Chemical adsorption occurs when the absorbate molecule is held on the adsorbent
surface by chemical forces asshort covalent chemical bonding occurs by the sharing of electrons.
Which of the following is true about Chemical adsorption :
(a) Non Specific
(b) Multi layer
(c) reversible
(d) Adsorbate molecules are held by chemical bonds
Oxygen adsorbed on the surface of Tungsten is an example of :
(a) Absorption
(b) Chemical Adsorption
(c) Physical adsorption
(d) None of these
If Tungstun adsorbs CO ,then in this case CO is :
(a) Absorbate
(b) Adsorbent
(c) Initially adsorbate then adsorbent
(d) None of these
Which of the following is an example of absorption :
(a) water on silica gel
(b) water on anhydrous CaCl2
(c) Hydrogen on Nickel
(d) Oxygen on metal surface
When the adsorbate molecules are held by van der waal forces , the adsorption is called as :
(a) Physical Adsorption
(b) Chemical adsorption
(c) Both (a) and (b)
(d) none of theseMCQ 1 Marks Sep-2021 • PSEB Class 12th -
Mole fraction of glycerine C3H5(OH)3 in solution containing 36 g of water and 46 g of glycerine is.
(a) 0.46
(b) 0.40
(c) 0.20
(d) 0.36MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Of the following 0.10 m aqueous solutions, which one will exhibit the largest freezing point depression ?
(a) KCl
(b) C6H12O6
(c) Al2(SO4)3
(d) K2SO4MCQ 1 Marks Sep-2021 • PSEB Class 12th -
A commercially available sample of H2SO4 is 15%by weight ( density =1.10gmL-1)its molality will be:
(a) 2.4m
(b) 1.08m
(c) 3.3m
(d) 1.8mMCQ 1 Marks Sep-2021 • PSEB Class 12th -
Which of the following is Haematite:
(a) Fe3O4
(b) Fe2O3
(c) CuO
(d) FeS2MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Which of the following is not a sulphide ore :
(a) Galena
(b) Iron pyrites
(c) Magnetite
(d) Copper glanceMCQ 1 Marks Sep-2021 • PSEB Class 12th -
Molar conductivity of 0.15 M solution of KCl at 298 K , if its conductivity is 0.0152 Scm-1will be
(a) 124 Scm2 mol-1
(b) 204 Scm2 mol-1
(c) 101 Scm2 mol-1
(d) 300 Scm2mol-1MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Standard electrode potential of Ni2+/Ni electrode, if the cell potential of the cell Ni|Ni2+( 0.01M) || Cu2+(0.1M)|Cu is 0.59 v given : E0Cu2+/Cu = 0.34V is
(a) -0.2205V
(b) 0.3205V
(c) + 0.014 V
(d) - 0.34VMCQ 1 Marks Sep-2021 • PSEB Class 12th -
A first order reaction takes 40 min for 30% completion .What will be its t1/2 :
(a) 77.7 min
(b) 52.5 min
(c) 46.2min
(d) 22.7 minMCQ 1 Marks Sep-2021 • PSEB Class 12th -
The rate constant for a reaction becomes double when temperature is raised from 270C to 370C .Iitsactivation energy will be :
(a) 106.5 kJmol-1
(b) 53.6 kJmol-1
(c) 46.2kJmol-1
(d) 98.7kJmol-1MCQ 1 Marks Sep-2021 • PSEB Class 12th -
The Increasing order of reducing power of the halogen acids is:
(a) HF <HCI <HBr <HI
(b) HI<HBr <HCI <HF
(c) HBr <HCI <HF <HI
(d) HCI < HBr <HF <HMCQ 1 Marks Sep-2021 • PSEB Class 12th -
The Hybridization of Xe in XeO2F4 is :
(a) SP3
(b) SP3d
(c) SP3d2
(d) SP3d3MCQ 1 Marks Sep-2021 • PSEB Class 12th-
Sep 2021 In XeF2 has hybridization :\r\n (a) SP3\r\n (b) SP3d \r\n (c) SP3d2\r\n (d) SP3d3
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Fluorine is the best oxidizing agent because of its :
(a) Highest electron affinity
(b) Highest reduction potential
(c) lowest electron affinity
(d) Highestoxidation potentialMCQ 1 Marks Sep-2021 • PSEB Class 12th -
NCl5 does not exist because :
(a) Nitrogen has high I.E
(b) Small size
(c) Absence of vacant d -orbitals
(d) High electronegativityMCQ 1 Marks Sep-2021 • PSEB Class 12th -
In XeF2 has hybridization :
(a) SP3
(b) SP3d
(c) SP3d2
(d) SP3d3MCQ 1 Marks Sep-2021 • PSEB Class 12th-
Sep 2021 The Hybridization of Xe in XeO2F4 is :\r\n(a) SP3\r\n(b) SP3d \r\n(c) SP3d2\r\n(d) SP3d3
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H3PO2 is:
(a) Monobasic
(b) Dibasic
(c) Tribasic
(d) None of theseMCQ 1 Marks Sep-2021 • PSEB Class 12th -
Which hydride of group 15 is most basic :
(a) NH3
(b) PH3
(c) SbH3
(d) AsH3MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Out of the following which one has highest boiling point :
(a) NH3
(b) PH3
(c) SbH3
(d) AsH3MCQ 1 Marks Sep-2021 • PSEB Class 12th -
The first compound of Xe was :
(a) Xe+2[ PtF6]
(b) XeO2F4
(c) XeO4
(d) Xe[ PtF6]MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Cause of lanthanoid contraction is :
(a) increasing nuclear charge
(b) decreasing nuclear charge
(c) poor shielding effect of 4f subshell
(d)increasing screening effectMCQ 1 Marks Sep-2021 • PSEB Class 12th -
The electronic configuration of Gd2+is (Z= 64 for Gd )
(a) [Xe] 4f1
(b) [Xe] 4f75d1
(c) [Xe] 4f8
(d) [Xe] 4f75d16s2MCQ 1 Marks Sep-2021 • PSEB Class 12th -
In which of the following case d-d transitions will occur ;
(a) Cu+
(b) Zn2+
(c) Cu2+
(d) Cd2+MCQ 1 Marks Sep-2021 • PSEB Class 12th -
The magnetic moment of a transition metal ion has been found to be 3.87 BM .It is probably
(a) Fe3+
(b) Cr3+
(c) Ti2+
(d) Ni2+MCQ 1 Marks Sep-2021 • PSEB Class 12th -
K2Cr2O7 is prepare from :
(a) CrO5
(b) FeO.Cr2O7
(c) FeO.Cr2O3
(d) K2CrO4MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Out of the following which one is diamagnetic :
(a) Cu2+
(b) Fe2+
(c) Zn2+
(d) Mn2+MCQ 1 Marks Sep-2021 • PSEB Class 12th -
The products formed in the following reaction at 873K and 6-7 bar Xe + F2 ? are :(1 : 5)
(a) XeF2
(b) XeF4
(c) XeF6
(d) XeO2F4MCQ 1 Marks Sep-2021 • PSEB Class 12th -
The common oxidation state shown by lanthanoids is :
(a) +1
(b) +5
(c) +3
(d) +7 Q33.MCQ 1 Marks Sep-2021 • PSEB Class 12th -
[Pt (NH3)4 ] [CuCl4] and [Cu (NH3)4 ] [PtCl4] are :
(a) Ionization isomers
(b) Coordination isomers
(c) linkage isomers
(d) Hydrate isomersMCQ 1 Marks Sep-2021 • PSEB Class 12th -
Which of the following ligands form a chelate :
(a) Acetate
(b) Oxalate
(c) Cyanide
(d) AmmoniaMCQ 1 Marks Sep-2021 • PSEB Class 12th -
IUPAC name of Na3 [ Fe (C2O4)3]
(a) sodium trioxalatoferrous(III)
(b) sodium trioxalatoferrate(III)
(c) sodium trioxalatoferrate(II)
(d) trisodiumtrioxalatoferrate(III)MCQ 1 Marks Sep-2021 • PSEB Class 12th -
Out of the following which one is not considered as transition element :
(a) Cu
(b) Ag
(c) Au
(d) HgMCQ 1 Marks Sep-2021 • PSEB Class 12th
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