ISC Chemistry Semester-1 Specimen Paper Solved Class -12

ISC Chemistry Semester-1 Specimen Paper Solved Class -12 for practice.  Step by step solutions of ISC Class-12 specimen model sample paper .  During solutions of semester-1  Chemistry specimen paper we explain with figure , graph, table whenever necessary so that student can achieve their goal in next upcoming exam of council. Visit official website CISCE for detail information about ISC Board Class-12.

ISC Chemistry Semester-1 Specimen Paper Solved Class -12

Board ISC
Class  12th (XII)
Subject Chemistry
Topic Semester-1 ISC Specimen Paper Solved
Syllabus  on bifurcated syllabus (after reduction)
session 2021-22
Question Type  MCQ/ Objective (as prescribe by council)
Total
question
Total=50 with all parts
Max
mark
70

ISC Chemistry Semester-1 Specimen Paper Solved Class -12


Question 1

Na and Mg crystallise in bcc and fcc structures respectively. The value of Z (number of atoms) for their crystals is:

(a) 8 and 14
(b) 2 and 4
(c) 14 and 8
(d) 6 and 4
Answer-

(b) 2 and 4

Question 2

Colligative properties depend on: 

(a) The nature of solute particles in solution
(b) The number of solute particles in solution
(c) The nature of solute and solvent particles
(d) The physical properties of solute particles in solution
Answer-

(b) The number of solute particles in solution

Question 3

On dilution, the specific conductance of a solution:

(a) Remains unchanged
(b) Increases
(c) Decreases
(d) First increases then decreases

Answer-

(a) Remains unchanged

Question 4

The flux used in the extraction of iron from haematite ore is: 

(a) Limestone
(b) Silica
(c) Coke
(d) Calcium phosphate

Answer-

(a) Limestone

Question 5

Which of the following xenon fluoride of xenon cannot be formed? 

(a) XeF2
(b) XeF4
(c) XeF6
(d) XeF3
Answer-

(d) XeF3

Question 6

The gas obtained on heating iodoform with silver powder is:

(a) Propane
(b) Ethane
(c) Ethyne
(d) Ethene
Answer-

(c) Ethyne

Question 7

Boiling point of ethyl alcohol is greater than diethyl ether due to: 

(a) Vander Waals forces
(b) London forces
(c) Polarity
(d) Hydrogen bonding
Answer-

(d) Hydrogen bonding

Question 8

In a face centred cubic lattice, atom ‘A’ occupies the corner positions and atom ‘B’ occupies the face centred positions. If one atom of ‘B’ is missing from one of the face centred points, the formula of the compound will be:

(a) AB2
(b) A2B3
(c) A2B5
(d) A2B
Answer-

(c) A2B5

Question 9

The standard reduction potential values of three metallic cations X, Y and Z are 0.52 V, – 3.03 V and -1.18 V respectively. The order of reducing power of the corresponding metals is:

(a) Y > Z > X
(b) X > Y > Z
(c) Z > Y > X
(d) Z > X > Y
Answer-

(a) Y > Z > X

Question 10

If molality of the dilute solution of a non-volatile, non-dissociating and non-associating electrolyte is doubled, the value of molal elevation constant or Ebullioscopic constant (Kb) will be:

(a) doubled
(b) halved
(c) tripled
(d) unchanged
Answer-

(d) unchanged

Question 11   (ISC Chemistry Semester-1 Specimen)

Extraction of zinc from zinc blende is achieved by :-

(a) Electrolytic reduction
(b) Roasting, followed by reduction with carbon
(c) Roasting, followed by reduction with another metal
(d) Roasting, followed by self-reduction
Answer-

(c) Roasting, followed by reduction with another metal

Question 12

The most powerful oxidizing agent is:

(a) Fluorine
(b) Chlorine
(c) Bromine
(d) Iodine
Answer-

(a) Fluorine

Question 13

During the course of SN
reaction, the intermediate species formed is:

(a) A free radical
(b) A carbanion
(c) A carbocation
(d) An intermediate complex
Answer-

(c) A carbocation

Question 14

Which type of defect has the presence of cations in the interstitial sites? 

(a) Schottky defect
(b) Vacancy defect
(c) Frenkel defect
(d) Metal deficiency defect

Answer-

(c) Frenkel defect

Question 15

Reaction between acetone and methyl magnesium chloride, followed by hydrolysis will give:

(a) tert-butyl alcohol
(b) iso-butyl alcohol
(c) iso-propyl alcohol
(d) sec-butyl alcohol
Answer-

(a) tert-butyl alcohol

Question 16

If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of solute is: 

(a) 0.2632
(b) 0.0102
(c) 0.0196
(d) 0.1045
Answer-

(c) 0.0196

Question 17

When zinc granule is dipped into copper sulphate solution, copper is precipitated because:

(a) Both copper and zinc have a positive reduction potential.
(b) Both copper and zinc have a negative reduction potential.
(c) Reduction potential of zinc is higher than that of copper.
(d) Reduction potential of copper is higher than that of zinc.

Answer-

(d) Reduction potential of copper is higher than that of zinc.

Question 18  (ISC Chemistry Semester-1 Specimen)

The optically active compound is: 

(a) Butan-1-ol
(b) Butan-2-ol
(c) Propan-1-ol
(d) 2-methyl-propan-1-ol
Answer-

(b) Butan-2-ol

Question 19

Chlorine reacts with cold and dilute NaOH under ordinary conditions to give: 

(a) NaCl and Cl2O
(b) NaCl and ClO2
(c) NaCl and NaClO
(d) NaCl and NaClO3
Answer-

(c) NaCl and NaClO

Question 20

Solutions which distil without any change in composition and temperature are called: 

(a) Ideal
(b) Super saturated
(c) Azeotropic
(d) Isotonic
Answer-

(c) Azeotropic

Question 21

The reaction: Sodium alkoxide + alkyl halide Ether + Sodium halide is called:

(a) Wurtz reaction
(b) Kolbe’s reaction
(c) Perkin’s reaction
(d) Williamson’s synthesis
Answer-

(d) Williamson’s synthesis

Question 22

Benzene diazonium chloride on hydrolysis gives: 

(a) Benzene
(b) Phenol
(c) Chlorobenzene
(d) Benzyl alcohol
Answer-

(b) Phenol

Question 23

The vacant space in body centred cubic lattice unit cell is:

(a) 32%
(b) 26%
(c) 48%
(d) 68%
Answer-

(a) 32%

Question 24

For a spontaneous reaction ∆Go and Eo cell will be respectively: [1]
(a) –ve and -ve
(b) +ve and +ve
(c) +ve and -ve
(d) –ve and +ve

Answer-

(d) –ve and +ve

Question 25

A liquid is mixed with ethanol and few drops of conc. H2SO4 is added. A compound with a fruity smell is formed. The liquid is:

(a) HCHO
(b) CH3CHO
(c) CH3COOH
(d) CH3COCH3
Answer-

(d) CH3COCH3

Question 26  (ISC Chemistry Semester-1 Specimen)

The chief ore of copper is copper pyrite (CuFeS2)

(i) How is the sulphide ore concentrated?

(a) By Gravity separation process
(b) By Froth-floatation process
(c) By Electromagnetic separation process
(d) By Leaching process

Answer-

(b) By Froth-floatation process

(ii) Copper is purified by electrolytic refining of blister copper. The correct statement about this process is:

(a) Impure copper strip is used as cathode
(b) Impurities do not settle as anode mud
(c) Pure copper deposits at cathode
(d) Acidified silver nitrate is used as electrolyte

Answer-

(c) Pure copper deposits at cathode

Question 27

The reaction: CH3Br + OH->CH3OH + Br –

(i) The expected mechanism of the above reaction is:

(a) SN 1 mechanism
(b) SN 2 mechanism
(c) SE 1 mechanism
(d) SE 2 mechanism

Answer-

(b) SN 2 mechanism

(ii) The above reaction is:

(a) Elimination reaction
(b) Nucleophilic addition reaction
(c) Nucleophilic substitution reaction
(d) Electrophilic substitution reaction

Answer-

(c) Nucleophilic substitution reaction

Question 28

For the extraction of metal, answer the following: 

(i) The smelting of iron ore in blast furnace involves all the processes except:

(a) Combustion
(b) Reduction
(c) Slag formation
(d) Sublimation

Answer-

(d) Sublimation

(ii) Which of the following metal is obtained by leaching the concentrated ore with dilute sodium cyanide solution, followed by treatment with zinc?

(a) Aluminium
(b) Iron
(c) Copper
(d) Silver
Answer-

(d) Silver

Question 29  (ISC Chemistry Semester-1 Specimen)

Phenol is heated with alcoholic KOH and chloroform: 

(i) What is the name of the reaction?

(a) Cannizzaro reaction
(b) Gattermann reaction
(c) Reimer –Tiemann reaction
(d) Kolbe reaction

Answer-

(c) Reimer –Tiemann reaction

(ii) What is the main product formed in this reaction?

(a) Salicylaldehyde
(b) Salicylic acid
(c) Aniline
(d) Phenyl isocyanide
Answer-

(a) Salicylaldehyde

Question 30

For IF7 molecule: 

(i) The structure of the given molecule is:

(a) Octahedral
(b) Tetrahedral
(c) Trigonal bipyramidal
(d) Pentagonal bipyramidal

Answer-

(b) Tetrahedral

(ii) The type of hybridization of the given molecule is:

(a) sp3 hybridisation
(b) sp3 d 3 hybridisation
(c) sp3d 2 hybridisation
(d) sp3 d hybridisation
Answer-

(d) sp3 d hybridisation

Question 31

Ethyl alcohol when reacts with PCl5 gives a compound (A). When compound (A) is treated with alc. KOH, compound (B) is formed along with KCl and H2O.

(i) The compound (A) is:

(a) C2H4Cl2
(b) CH3CHO
(c) C2H5Cl
(d) CH3OH

Answer-

(c) C2H5Cl

(ii) The compound (B) is:

(a) C2H2
(b) C2H4
(c) C2H6
(d) C2H5OH

Answer-

(b) C2H4

Question 32  (ISC Chemistry Semester-1 Specimen)

Copper pyrite or chalcopyrite (CuFeS2) is the main ore of copper. The extraction of copper from its ore involves, concentration, partial roasting, removal of iron and selfreduction.

(i) On heating the mixture of Cu2O and Cu2S, which one of the following will be obtained?

(a) Cu2SO3
(b) Cu + SO3
(c) CuO + CuS
(d) Cu + SO2

Answer-

(d) Cu + SO2

(ii) Iron is removed during the extraction of copper as:
(a) FeO
(b) FeS
(c) FeSiO3
(d) Fe2O3

Answer-

(c) FeSiO3

Question 33

Conversion of Chlorobenzene into phenol.

(i) Which of the following statements is correct for the above conversion?

(a) Heating it with alc. KOH at room temperature
(b) Heating it with aqueous NaOH at 623 K under pressure followed by acidification with dilute HCl
(c) Heating it with CuCN followed by acidification with dilute HCl
(d) Heating it with sodium metal in the presence of dry ether

Answer-

(b) Heating it with aqueous NaOH at 623 K under pressure followed by acidification with dilute HCl

(ii) What is the name of the above reaction?

(a) Dow process
(b) Wurtz reaction
(c) Sandmeyer’s reaction
(d) Kolbe’s reaction
Answer-

(a) Dow process

Question 34

With reference to XeF6 molecule, answer the following questions. 

(i) What is the hybridisation of Xe atom in the given molecule?

(a) sp3 d 3
(b) sp3 d 2
(c) sp3
(d) sp3 d

Answer-

(a) sp3 d 3

(ii) What is the geometry of this molecule?

(a) Distorted octahedral
(b) Square planer
(c) Pyramidal
(d) Tetrahedral
Answer-

(a) Distorted octahedral

Question 35 (ISC Chemistry Semester-1 Specimen)

An unknown alcohol is treated with Lucas reagent to determine whether the alcohol is primary, secondary or tertiary.

(i) Which alcohol reacts fastest and by what mechanism?

(a) Tertiary alcohol by SN 2
(b) Secondary alcohol by SN 1
(c) Tertiary alcohol by SN 1
(d) Secondary alcohol by SN 2

Answer-

(c) Tertiary alcohol by SN 1

(ii) What is the chemical composition of the Lucas reagent used above?

(a) Anhydrous zinc chloride in concentrated HCl
(b) Anhydrous aluminium chloride in concentrated HCl
(c) Anhydrous lead chloride in concentrated HCl
(d) Anhydrous barium chloride in concentrated HCl
Answer-

(a) Anhydrous zinc chloride in concentrated HCl

Question 36

Ozone is prepared from oxygen: 

(i) Which method is used in the above preparation?

(a) Oxidation at high temperature
(b) Oxidation using catalyst
(c) Silent electric discharge
(d) Reduction at high temperature

Answer-

(c) Silent electric discharge

(ii) The ozone obtained above acts as a:

(a) reducing agent
(b) oxidising agent
(c) decomposer
(d) dehydrating agent
Answer-

(b) oxidising agent

Question 37

Copper metal crystallises with face centred cubic unit cell. If the edge length of copper atom is 361.5 pm. (Atomic weight of Cu = 63.5, NA = 6.02 x 1023 mol-1)

(i) The density of copper metal is:

(a) 7.86 g/cm3
(b) 8.93 g/cm3
(c) 9.76 g/cm3
(d) 10.5 g/cm3

Answer-

(b) 8.93 g/cm3

(ii) The radius of copper metal is:

(a) 180.75 pm
(b) 156.53 pm
(c) 127.79 pm
(d) 104.86 pm
Answer-

(c) 127.79 pm

Question 38  (ISC Chemistry Semester-1 Specimen)

An aqueous solution containing one gram of urea (molecular weight = 60) boils at 100.25oC. The same solution freezes at -0.894 oC. The aqueous solution containing 3 gram of glucose (Molecular weight = 180) in the same volume of solution:

(i) What is the boiling point of glucose?

(a) 100.75 oC
(b) 100.50 oC
(c) 100.25 oC
(d) 100.08 oC

Answer-

(c) 100.25 oC

(ii) What is the freezing point of glucose?

(a) +0.894 oC
(b) -0.894 oC
(c) +0.447 oC
(d) -0.447 oC

Answer-

(b) -0.894 oC

Question 39

When two Faradays of electricity is passed through an aqueous solution of CuSO4 and an aqueous solution of AgNO3. (Atomic weight of Cu = 63.5 g mol-1 , Ag = 108 g mol-1)

(i) The mass of copper deposited at the cathode is:

(a) 127.02 g
(b) 63.50 g
(c) 31.75 g
(d) 15.87 g

Answer-

(b) 63.50 g

(ii) The mass of silver deposited at the cathode is:

(a) 54 g
(b) 108 g
(c) 216 g
(d) 270 g
Answer-

(c) 216 g

Question 40

Gold has cubic crystal whose unit cell has an edge length of 407.9 pm. Density of gold
is 19.3 g cm-3. Atomic weight of gold is 197 g mol-1. (NA = 6.02 x 1023 mol-1)

(i) The number of atoms (Z) in a unit cell of gold is:

(a) 1
(b) 2
(c) 3
(d) 4

Answer-

(d) 4

(ii) The type of crystal structure of gold is:

(a) Simple cubic unit cell
(b) Body centred cubic unit cell
(c) Face centred cubic unit cell
(d) Side centred cubic unit cell
Answer-

(c) Face centred cubic unit cell

Question 41  (ISC Chemistry Semester-1 Specimen)

A solution of sucrose (molecular weight 342 g mol-1) has been prepared by dissolving 68.4 g of sucrose in 1000 g of water.(Kf for water = 1.86 K kg mol-1)

(i) The freezing point of the solution obtained will be:

(a) -0.52 oC
(b) +0.52 oC
(c) -0.372 oC
(d) +0.372 oC

Answer-

(c) -0.372 oC

(ii) The molality of sucrose solution will be:

(a) 0.1
(b) 0.2
(c) 0.3
(d) 0.4
Answer-

(b) 0.2

Question 42

The standard electrode potential for the reaction is:

(I)
(II)

(i) The Eo cell will be:

(a) 0.66 V
(b) 0.88 V
(c) 0.94 V
(d) 1.08 V

Answer-

(c) 0.94 V

(ii) The value of standard Gibbs energy (∆Go) will be:(F = 96,000 C mol-1)

(a) -181.42 kJ
(b) -90.71 kJ
(c) -45.36 kJ
(d) -22.68 kJ

Answer-

(a) -181.42 kJ

Question 43  (ISC Chemistry Semester-1 Specimen)

A metal has face centred cubic lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g/cm3 . (NA = 6.023 x 1023 mol-1 )

(i) The molar mass of the metal is:

(a) 20 g mol-1
(b) 27 g mol-1
(c) 30 g mol-1
(d) 40 g mol-1

Answer-

(b) 27 g mol-1

(ii) The radius of the metal atom in centimetre (cm) is:

(a) 103.29 x 10-10 cm
(b) 125.63 x 10-10 cm
(c) 142.81 x 10-10 cm
(d) 175.76 x 10-10 cm

Answer-

(c) 142.81 x 10-10 cm

Question 44

A binary solution contains 92 g ethyl alcohol and 72 g water. (Atomic weight of C = 12, H =1, O =16)

(i) Mole fraction of ethyl alcohol is:

(a) 0.40
(b) 0.80
(c) 0.66
(d) 0.33

Answer-

(d) 0.33

(ii) Mole fraction of water is:

(a) 0.33
(b) 0.66
(c) 0.20
(d) 0.80
Answer-

(b) 0.66

Question 45

The limiting molar conductivities (˄∞m) for NaCl, KBr and KCl are 126, 152 and 150 ohm-1 cm2 mol-1 respectively.

(i) The molar conductivity at infinite dilution for NaBr is:

(a) 128 ohm-1 cm2 mol-1
(b) 176 ohm-1 cm2 mol-1
(c) 278 ohm-1 cm2 mol-1
(d) 302 ohm-1 cm2 mol-1

Answer-

(a) 128 ohm-1 cm2 mol-1

(ii) The law applied to determine the molar conductivity of infinite dilution is known as:

(a) Faraday’s Law
(b) Avogadro’s Law
(c) Kohlrausch’s Law
(d) Ohm’s Law

Answer-

(c) Kohlrausch’s Law

Question 46

Assertion: Haloalkanes when treated with alcoholic KCN forms alkane nitrile as a major product.

Reason: Potassium cyanide is a covalent compound.

(a) Assertion is false but reason is true.
(b) Assertion is true but reason is false.
(c) Both assertion and reason are false.

(d) Both assertion and reason are true and reason is the correct explanation of the assertion.
Answer-

(b) Assertion is true but reason is false.

Question 47

Assertion: Iron is found free in nature.
Reason: Iron is highly reactive element.

(a) Assertion is false but reason is true.
(b) Assertion is true but reason is false.
(c) Both assertion and reason are true but reason is not correct explanation of the assertion.
(d) Both assertion and reason are true and reason is the correct explanation of the assertion.

Answer-

(a) Assertion is false but reason is true.

Question 48  (ISC Chemistry Semester-1 Specimen)

Assertion: Ethers are more volatile than alcohols having the same molecular formula.
Reason: Alcohols have intermolecular hydrogen bond.

(a) Assertion is false but reason is true.
(b) Assertion is true but reason is false.
(c) Both assertion and reason are true but reason is not correct explanation of the assertion.
(d) Both assertion and reason are true and reason is the correct explanation of the assertion.
Answer-

(d) Both assertion and reason are true and reason is the correct explanation of the assertion.

Question 49

Assertion: SO2 decolorises pink colour of acidified KMnO4 solution.
Reason: SO2 is an oxidising agent

(a) Assertion is false but reason is true.
(b) Assertion is true but reason is false.
(c) Both assertion and reason are true but reason is not the correct explanation of the assertion.
(d) Both assertion and reason are true and reason is the correct explanation of the assertion.
Answer-

(b) Assertion is true but reason is false.

Question 50

Assertion: Sulphide ores are concentrated by froth floatation process.
Reason: Sulphide ores are wetted by pine oil forming the froth while impurities are vetted by water.

(a) Both assertion and reason are correct and reason is the correct explanation of the assertion.
(b) Both assertion and reason are correct but reason is not the correct explanation of the assertion.
(c) Assertion is correct and the reason is wrong.
(d) Both assertion and reason are wrong.

Answer-

(a) Both assertion and reason are correct and reason is the correct explanation of the assertion.

— End of Solution of ISC Chemistry Specimen Paper Sem-1 :– 


Step by Step Solution of ISC Chemistry Specimen Paper Sem-1 


Video Solution ISC Chemistry Specimen Paper  Sem-1 (From Q-1 to 25)


Video Solution ISC Chemistry Specimen Paper  Sem-1 (From Q-26 to 50)


–: Also visit :–

Thanks

Please share with your ISC friends if it is helpful

4 thoughts on “ISC Chemistry Semester-1 Specimen Paper Solved Class -12”

  1. Thank a lot for uploading the answer key with proper solution…Although the question (30) solved is correct the answer mentioned is wrong… Please see to it

    Reply

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.