RBSE Class 12 E-Chemistry Self Evaluation Test Papers in English

Students must start practicing the questions from RBSE 12th Chemistry Model Papers E-Chemistry Self Evaluation Test Papers in English Medium provided here.

RBSE Class 12 E-Chemistry Self Evaluation Test Paper 1 in English

Section – A
Multiple Choice Questions (MCQs)

Question 1.
Choose the correct option :
(i) Which of the following is not an ore of aluminimum? (1)
(a) Bauxite
(b) Commdum
(c) Diaspore
(d) Azurite

(ii) The density of cubic unit cell can be given by following formula: (1)
(a) \(\frac{n \times \mathrm{M}}{a^{3} \times \mathrm{N}_{\mathrm{A}}}\)
(b) \(\frac{\mathrm{N}_{\mathrm{A}} \times n}{\mathrm{M} \times a^{3}}\)
(c) \(\frac{a^{3} \times \mathrm{M}}{n \times \mathrm{N}_{\mathrm{A}}}\)
(d) None of these

(iii) Which one of the following has an optical isomer? (1)
(a) [Co(H₂O)₄(en)]³⁺ [en = ethylenediamine]
(b) [Zn(en)₂]²⁺
(c) [Zn(en)(NH₃)₂]³⁺
(d) [Co(en)₃]³⁺

(iv) Which of the following species will be the strongest Lewis acid? (1)
(a) Fe⁰
(b) Fe³⁺
(c) Fe²⁺
(d) Fe¹⁺

(v) Which of the ions will given colourless aqueous solution? (1)
(a) Ni²⁺
(b) Fe²⁺
(c) Fe²⁺
(d) Fe⁺

(vi) An alcohol is less volatile than either having same molecular formula. Its is due to : (1)
(a) interTmolecular H-bonding in alcohol
(b) inter-molecular H-bonding in ethers
(c) dipolar nature of ethers
(d) resonance in alcohol

(vii) Which of the following compounds is not obtained during the reaction of methane and chlorine in the presence of sun light ? (1)
(a) CHCl₃
(b) CH₃Cl
(C) CH₂Cl₂
(d) CH₃CH₂CH₃

(viii) Rate of reaction : (1)
(a) increases with increase in temperature
(b) decreases with increase in temperature
(c) does not depend on temperature
(d) does not depend on concentration

(ix) Which is correct for benzene and toulene? (1)
(a) ∆H_mix ≠ 0
(b) ∆V_mix ≠ 0
(c) ∆H_mix = 0
(d) None of these

Question 2.
Fill in the blanks:
(i) For ideal solution ∆X_mixing is equal to ____________.(1)

(ii) Iron ore, Iron pyrite (FeS₂) is also known as ____________. (1)

(iii)

reaction is known as ____________. (1)

(iv) Internal salts of amine compounds are known as ____________. (1)

Question 3.
Very Short Answers Type Questions
(i) What types of ores can be concentrated by magnetic separation method? (1)

(ii) Name the following coordination compound : K₃[CrF₆]. (1)

(iii) What is the function of collectors in the froth floatation process for the concentration of ores? (1)

(iv) Which point defect of its crystals decreases the density of a solid? (1)

(v) Ortho-nitroplhenol is more acidic than ortho methoxyphenol. Why? (1)

(vi) How many methyl amine be preferentially converted to methyl isocyanide? (1)

(vii) Enumerate the reactions of glucose, which cannot be explained by its open chain structures. (1)

(viii) Write equation of the nitration of anisole. (1)

Section – B
Short Answer Type Questions

Question 4.
What do you understand by denticity of a ligand? (1½)

Question 5.
Express the rate of the following in terms of ammonia. (1½)

Question 6.
Define order of a reaction. (1½)

Question 7.
Write down the structures and names of the products formed when D-glucose is treated with
(i) Bromine water
(ii) Hydrogen Iodide (Prolonged heating). (1½)

Question 8.
State Henry’s law and mention some important applications. (1½)

Question 9.
Calculate the mass of a non-volatile solute (molar mass 40 g mol^-1) which should be dissolved in 114g of octane to reduce its vapour pressure to 80%. (1½)

Question 10.
A reaction is second order w.r.t. A and first order w.r.t. B. (1½)
(i) Write the differential rate equation.
(ii) How is the rate affected on increasing the concentration of A three times?
(iii) How is the rate affected when the concentrations of both A and B are doubled?

Question 11.
The rate constant for a first order reaction is 60s^-1. How much time will it take to reduce the initial concentration of the reactant to its \(\frac{1}{16}\) th value? (1½)

Question 12.
Show how are the following alcochols prepared by the reaction of suitable Grignard reagent on methanol? (1½)

Question 13.
What is meant by crystal field splitting energy? On the basis of crystal field theory, write the electronic configuration of d⁴ in terms of t_2g, and e_g in an octahedral field when (1½)
(i) D₀ > P
(ii) D₀ < P.

Question 14.
Write the reactions involved in the following: (1½)
(i) Hell-Voihard Zelinsky reaction
(ii) Decarboxylation reaction

Question 15.
What essential and non-essential amino acids in human food? Give one example of each type. (1½)

Section – C
Long Answer Type Questions

Question 16.
(a) An element has an atomic mass 93g mol^-1 and density of 11.5gcm^-3. If the edge length of its unit cell is 300 pm, identify the type of unit cell.
(b) Write any two differences between amorphous solids and crystalline solids. (3)
OR
(a) An element has an atomic mass 93 g mol^-1 and density 11.5 g cm^-3. If the edge length of its unit cell is 300 pm, identify the type of unit cell.
(b) Write any two differences between amorphous solids and crystalline solids. (3)

Question 17.
(a) Calculate the number of unit cells in 8. 1 g of aluminium if it crystallizes in a.f.c.c. structure. (Atomic mass of Al = 27g mol^-1)
(b) Give reasons:
(i) In stoichiometric defects, NaCl exhibits Schottky defect and not Frenkel defect.
(ii) Silicon on dopping with Phosphorous form n-type semiconductor.
(iii) Ferrimagnetic substances show between magnetism and anti-ferromagnetic substances. (3)
OR
In pseudo-first-order hydrolysis of ester water the following results were obtained:

(i) Calculate the average rate of reaction between the time interal 30 to 60 seconds.
(ii) Calculate the pseudo-first Order rate constant for the hydolysis of ester,

Question 18.
A reaction is first order in A and second order in B.
(i) Write the differential rate equation.
(ii) How is the rate affected on increasing the concentration of B three times,
(iii) How is the rate affected when the concentration of both A and B are doubled? (3)
OR
Vapour pressure of chloroform (CHCl₃) and dichloromethane (CH₂Cl₂) at 298 K are 200 mm Hg and 415 mm Hg respectively.
(1) Calculate the vapour pressure of the solution prepared by mixing 25.5 g of CHCl₃ and 40g of CH₂Cl₂ at 298 K and
(ii) mole fractions of each component in vapour phase. (3)

Section – D
Essay Type Questions

Question 19.
Write the structures of products of the following reactions : (4)

Arrange the following compounds in increasing order of their reactivity ¡n nucleophilic addition reactions:
(i) Ethanal, Propanal, Propanone, Butanone
(ii) Benzaldehyde, p-Tolualdehyde, p-Nitrobenazalehyde. Acetophenonc’

Question 20.
Identify A, B, C, D E, R and R¹ in the following:

Predict all the alkenes that would be formed be dehydrohalogenation of the following halides with sodium ethoxide in ethanol and identify the major alkene.
(i) 1-Bromo-1-methylcyclohexane,
(ii) 2-Chloro-2-methyl butane.
(iii) 3-Bromo-2, 2, 3-trimethyl pentane. (4)

RBSE Class 12 E-Chemistry Self Evaluation Test Paper 2 in English

Section – A
Multiple Choice Questions (MCQs)

Question 1.
Choose the correct option :
(i) Copper can be extracted from its sulphide ore by : (1)
(a) electrolytic reductions
(b) formation of complex
(c) auto reduction
(d) carbon reduction

(ii ) Magnetite is an ore of: (1)
(a) Mg
(b)Ag
(c) Mn
(d) Fe

(iii) ’A’ in following reaction is : (1)

Which one of the following is least acidic?
(a) Phenol
(b) CH₃NC
(c) p-chlorophenol
(d) CH₃NO₂

(v) The rate of reaction of a substance depends on : (1)
(a) active mass
(b) molecular weight
(c) atomic weight.
(d) equivalent weight

(vi) If CsBr is crystallized in bcc lattice and edge length of unit cell is 436.6 pm. If atomic masses of Cs and Br are 133 g/mol and 80 g/mol^and Avogadro number is 6.022 × 10²³, then density of CsBr will be : (1)
(a) 0.425 g cm0^-3
(b) 8.25 g cm^-3
(c) 4.25 g cm^-3
(d) 42.5 g cm^-3

(vii) Which one of the following is not starting material for preparing CHI₃ (iodoform): (1)
(a) CH₃OH
(b)C₂H₅OH
(c) CH₃CHO
(d) (CH₃)₂CO

(viii) A substance is crystallized in face-centred cubic structure. Atom A is present at each comer and atom B at centre of each face. The correct composition of A_xB_y will be. (1)
(a) AB₃
(b) A₄B₃
(c) A₃B
(d) None of these

(ix) The product ‘D’ in following reaction is: (1)

(a) Ester
(b) Amine
(c) Acid
(d) Alcohol

Question 2.
Fill is the blanks :
(i) A radioactive substance disintegrates 75% in 50s, then its half life period is __________. (1)

(ii) In the first transition scries, the maximum number of oxidation states is shown by __________. (1)

(iii) Di-halogen compound in which both halogen atom present on single carbon atom is known as __________. (1)

(iv)

Question 3.
Very Short Answer Type Questions :
(i) For a reaction R → P, half-life (t_1/2) is observed to be independent of the initial concentration of reactants. What
is the order of reaction? (1)

(ii) What are the collectors used in froth floatation process? Name a substance that can be used as such? (1)

(iii) Differentiate between a mineral and an ore; (1)

(iv) Name the bases present in RNA. Which one of these is not present in DNA? (1)

(v) Define the term osmotic pressure. (1)

(vi) Give a chemical test to distinguish between Benzoic acid and Phenol. (1)

(vii) In the series Sc(Z = 21) to Zn(Z = 30), the enthalpy of atomisation of zinc is the lowest, i.e., 126 kJ mol^-1. Why? (1)

(viii) Give the IUPAC name of the following compound : (1)

Section – B
Short Answer Type Questions

Question 4.
What are ambident nucleophiles? Explain with an example. (1½)

Question 5.
For a reaction :

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

Question 6.
Differentiate between fibrous proteins and globular proteins. (1½)

Question 7.
What is the effect of denaturatiori on the structure of proteins? (1½)

Question 8.
Write the structures of the following organic halogen compounds : (1½)
(i) 4-tert-Butyl-3-idodeptane
(ii) 4-Bromo-3-methylpent-2ene

Question 9.
Silver crystallizes in face-centred cubic unit cell. Each side of this unit cell has a length of 400 pm. Calculate the radius of the silver atom. (Assume the atoms just touch each other on the diagonal across the face of the unit cell. That is each face atom is touching the four corner atoms.) (1½)

Question 10.
(a) Based on the nature of intermolecular forces, classify the following solids : Silicon carbide, Argon (1½)
(b) ZnO turns yellow on heating. Why?
(c) What is meant by groups compounds? Give an example.

Question 11.
Indicate the steps in the preparation of: (1½)
(i) K₂Cr₂O₇ from chromite ore
(ii) KMnO₄ from pyrolusite ore.

Question 12.
A first order reaction takes 100 min for completion of 60% of the reaction. Find the time when 90% of the reaction will be completed. (1½)

Question 13.
What are alloys? Name an important alloy which contains some of the lanthanoid metals. Mention it uses. (1½)

Question 14.
For the complex [NiCl₄]^2-, write: (1½)
(i) the IUPAC name
(ii) the hybridisation type
(iii) the shape of the complex (Atomic no. of Ni = 28)

Question 15.
What are metal carboxyls? Discuss bonding hi metal carboxyls. (1½)

Section – C
Long Answer Type Questions

Question 16.
Explain the following: (3)
(a) CO(NH₃)₅Cl₃ gives three ions in solution.
(b) Geometrical isomerism is not possible in tetrahedral complexes.
OR
(a) Define chelate and chelating ligand. Give one example of each.
(b) Explain briefly the role of coordiantion compounds in analytical chemistry and extraction of metals. (3)

Question 17.
Explain:
(a) Ethers posses dipole moment even if the alkyl radicals in the molecule are identical.
(b) Boiling point of ethers are lower than their corresponding alcohols. (3)
OR
(a) Explain how an —OH group attached to a carbon in the benzene ring activates benzene towards substitution?
(b) Discuss the oxidation of 1°, 2° and 3° alcohols. (3)

Question 18.
(a) Why is aniline less basic than methylamine? (3)
(b) What happens when aniline reacts with K₂Cr₂O₇ and H₂S0₄?
OR
How are diazonium saltes prepared? How does benzene diazonium chloride react with : (3)
(a) Water
(b) Sodium nitrate

Section – D
Essay Type Questions

Question 19.
(i) State Raoult’s law for a solution containing volatile components. How does Raoult’s law become a special case of Henry’s law? (4)
(ii) Explain why a solution of chloroform and acetone shows negative deviation from Raoult’s law?
OR
(i) State Henry’s law and mention some important applications
(ii) Differentiate between molarity and molality of a solution. How can we change the molality value of a solution into molarity value? (4)

Question 20.
(a) How will you convert acidic acid into: (4)
(i) acetamid
(ii) acetyl chloride
(b) Although p-hydroxybenzoic acid is less acidic than benzoic acid, ortho-hydroxy benzonic acid is about 15 times acidic than benzoic acid. Explain.
OR
An organic compound with formula C₉H₁₀O forms a 2,4-DNP derivative, reduces Tollen’s reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives, 1, 2-benzene dicarboxylic acid. Identify the compound. (4)

RBSE Class 12 E-Chemistry Self Evaluation Test Paper 3 in English

Section – A
Multiple Choice Questions (MCQs)

Question 1.
Choose the correct option:
(i) The maximum oxidation state of osmium is : (1)
(a) + 6
(b) + 7
(c) + 8
(d) + 5

(ii) The highest magnetic moment is shown by the transition metal with the configuration : (1)
(a) 3d²
(b) 3d⁵
(c) 3d¹
(d) 3d⁹

(iii) Froth floatation process is used to concentrate which type of ores? (1)
(a) Sulphide ores
(b) Phosphate ores
(c) Silicate ores
(d) Oxide ores

(iv) Gravity separation method is used to concentrate which type of ores? (1)
(a) Sulphide ores
(b) Phosphate ores
(c) Silicate ores
(d) Oxide ores

(v) Denatured alcohol is : (1)
(a) Ethanol + Methanol
(b) Rectified spirit
(c) Ethanol
(d) Rectified spirit + methanol + naphtha

(vi) According to Raoult’s law, the relative lowering of vapour pressure of solution of non-volatile solute is : (1)
(a) equal to precentage of solute
(b) equal to mole fraction of solute
(c) equal to mole fraction of solvent
(d) equal to mass precentage of solute

(vii) The addition of a catalyst during a chemical reaction alters which of the following quantities?
(a) activation energy
(b) entropy
(c) internal energy
(d) enthalpy

(viii) The rate of reaction on doubling the active mass of A by keeping active mass of B constant in the reaction 2A + B → Product will be (1)
(a) twice as before
(b) four times as before
(c) half as before
(d) one fourth as before

(ix) Which of the solution represents positive deviation? (1)
(a) Ethyl bromide + Methyl bromide
(b) Cyclohexane + Ethanol
(c) Chloroform + Acetone
(d) None of the above

Question 2.
Fill in the blanks :
(i) The number of tetrahedral voids per atom in a crystal lattice is __________. (1)

(ii) [EDTA]^-4 is __________ dentate ligand. (1)

(iii) Alkyl halides are insoluble in water because they do not form __________ with water. (1)

(iv) Distinguish between ethylamine and aniline is done by __________ test. (1)

Question 3.
Very Short Answer Type Questions :
(i) What happens when ethyl chloride is treated with aqueous KOH? (1)

(ii) Write a feature which will distinguish metallic solid from an ionic solid. (1)

(iii) The C-O bond is much shorter in phenol than in ethanol. Give reason: (1)

(iv) Write the IUPAC name of the following compound: (1)

(v) Write the IUPAC name of the given compound: (1)

(vi) Out of

and which one is more acidic? (1)

(vii) Identify the reaction order from the following rate constant, k = 2.3 × 10^-5 L mol^-1 s^-1. (1)

(viii) Name the products of hydrolysis of sucrose. Why is sucrose flot a reducing sugar? (1)

Section – B
Short Answer Type Questions

Question 4.
How is the eolligative property changed when the solute undergoes association in solution? (1½)

Question 5.
What are essential and non-essential amino acids in human food? Give one example of each type. (1½)

Question 6.
Classify each of the following as being either a p-type or a n-type semiconductors: (1½)
(i) Ge doped with In
(ii) Si doped with B.

Question 7.
Define roult’s low and derive it. (1½)

Question 8.
Differentiate between reducing and non-reducing sugars. (1½)

Question 9.
For the reaction: (1½)
2N₂O₅(g) → 4NO₂(g) + O₂(g) the rate of formation of NO₂(g) is 2.8 x 10 3 Ms”5. Calculate the rate of disappearance of N₂O₅(g).

Question 10.
For a chemical reaction, R → P, the variation in the concentration of R versus time (t) plot is given as: (1½)

(i) Predict the order of the reaction.
(ii) What is the slope of the curve?

Question 11.
A compound forms hep structure. What is the total number of voids in 0.5 mol of it? Flow many of these are tetrahedral voids? (1½)

Question 12.
There, are two -NH₂ groups in semi-carbazide. However, only one is involved in the formation of semi-carbazone. Give reason. (1½)

Question 13.
Complete the following reaction: (1½)

Question 14.
Explain hydroboration reaction with an example. (1½)

Question 15.
Give chemical reaction ¡or these reactions: (1½)
(a) Williumson ether synthesis
(b) Reimer-Ticmann reaction.

Section – C
Long Answer Type Questions

Question 16.
What is lanthanoid contraction? What are the main consequences of lanthanoid contraction? (3)
OR
Draw structures of chromate and dichromate ion. Write the a tion of heat on potassium dichromate and potassium permagnate. (3)

Question 17.
(a) Grignard reagent should be prepared under anhydrous conditions? Explain:
(b) Give two uses of iodoform.
(e) Wiite the formu’a of DDT. (3)
OR
(a) Why are haloarenes less reactive than haloalkanes? Lxplain.
(b) Give two uses of freons.
(C) How is chlorobenzene prepared from benzene diazonium chloride? (3)

Question 18.
(a) Why is aniline less basic than methylamine? (3)
(b) How is the activation of benzene ring by amino group reduced by acetylating aniline diving nitration.
(c) What happens when aniline reacts with K₂Cr₂O₇ and H₂SO₄?
OR
(a) Explain why aniline does not undergo Friedel-crafts reaction.
(b) Why are aliphatic amines more basic than aromatic amines?
(c) How sulphanilic acid prepared from aniline. (3)

Section – D
Essay Type Questions

Question 19.
(a) Explain bonding in coordination compounds with the help of crystal field theory. (4)
(b) Draw the two geometrical isomers of the complex compound [Pt(NH₄)₂Cl₂]
(c) Explain coordination sphere with one example.
OR
(a) What is crystal field splitting and crystal field splitting energy? Draw and explain the splitting of (f-orbitals in an Octahedral-field of ligands.
(b) What do you understand by weak fields and strong field ligands? (4)

Question 20.
(a) Why are the boiling points of carboxylic acids higher than the alcohols of comparable molecular mass? (4)
(b) Complete the reaction

OR
(a) Why ethanoic acid is weaker acid than benzoic acid?
(b) How will you convert benzoic acid to benzaldehyde?
(c) Write Hunsdiecker reaction. (4)

RBSE Class 12 E-Chemistry Self Evaluation Test Paper 4 in English

Section – A
Multiple Choice Questions (MCQs)

Question 1.
Choose the correct option:
(i) The ionisation isomer of [Cr(H₂O)₄Cl(N0)₂]Cl is : (1)
(a) [Cr(H₂O)₄(O₂N)]Cl₂
(b) [Cr(H₂O)₄4Cl₂](NO₂)
(c) [Cr(H₂O)₄Cl(ONO)]Cl
(d) [Cr(H₂O)Cl₂(NO₂)]H₂O

(ii) In which of the following pairs, both the ions are coloured in an aqueous solution? (1)
(a) Sc³⁺, CO²⁺
(b) Ni²⁺,Cu⁺
(c) Ni²⁺, Ti³⁺
(d) Sc³⁺, Ti³⁺

(iii) Which of the following reaction does not form amine? (1)

(iv) In which glucose does not classified? (1)
(a) Hexose
(b) Carbohydrate
(c) Oligosaccharide
(d) Aldose

(v) Which of the following dose not give Cannizzaro reaction : (1)
(a) trimethyl acetaldehyde
(b) benzaldehyde
(c) acetaldehyde
(d) formaldehyde

(vi) The rate constant and rate of reaction is similar when the concentration of reactants is : (1)
(a) unity
(b) zero
(c) both of these
(d) none of these

(vii) Which one of the following reagent is not used for preparing alkyl halide from alcohol? (1)
(a) HCl + ZnCl₂
(b)NaCl
(c)PCl₅
(d) SOCl₂

(viii) Iron can be extracted from its oxide ores by which method? (1)
(a) Carbon reduction method
(b) Auto reduction method
(c) Carbon mono oxide reduction method
(d) Complex formation method

(ix) Which of the following alcohols would react fastest with Lucas reagent? (1)
(a) 2-Butanol
(b) 1 -Butanol
(c) 2-Methyl propanol
(d) 2-Methylpropan-2-ol

Question 2.
Fill in the blanks :
(i) The oxidation state of nickel in K₄[Ni(CN)₄] is ___________. (1)

(ii) The empty space in hep is ___________. (1)

(iii) Tibermann nitroso reaction is for the detection of ___________ amines. (1)

(iv) Toluene reacts with Cl₂ in the presence of FeCl₃ to give ___________. (1)

Question 3.
Very Short Answer Type Questions :
(i) State the main advantage of molality over molarity as the unit of concentration. (1)

(ii) Name the deficiency diseases resulting from lack of Vitamins A and E in the diet. (1)

(iii) Name one water soluble vitamin which is a powerful antioxidant Give its one natural source. (1)

(iv) Which point defect in its crystal units increases the density of a solid? (1)

(v) Why does the rate of a reaction not remain constant throughout the reaction process? (1)

(vi) What is the role of cryolite in the metallurgy of aluminium? (1)

(vii) When a coordination compound COCl₃.6NH₃ is mixed with AgNO₃, 3 moles of AgCl are precipitated per mole of the compound. Write structural formula of the complex. (1)

(viii) What type of azeotropic mixture will be formed by a solution of acetone and chloroform? Justify on the basis of strength of intermolecular interactions that develop in the solution. (1)

Section – B
Short Answer Type Questions

Question 4.
Out line the principles of refining of metals by the following methods: (1½)
(i) Zone refining
(ii) Electrolytic refining

Question 5.
CuSO₄.5H₂O is blue in colour while CuSO₄ is colourless. Why? (1½)

Question 6.
Write the structures of the following organic halogen compounds: (1½)
(i) p-Bromochlorobenzene
(ii) 1-Chloro-4-ethylcyclohexane

Question 7.
Draw the sturcture of major monohalo product in each of the following reactions : (1½)

Question 8.
How is copper reduce from low grade copper ores? (1½)

Question 9.
Why do compounds having similar geometry have different magnetic moment. (1½)

Question 10.
For the reaction A → B, the rate of reaction becomes three times when the concentration of A is increased by nine times. What is the order of reaction? (1½)

Question 11.
What do you understand by the rate law and rate constant of a reaction? Identify the order of a reaction, if the units of its rate constant are: (1½)
(i) L^-1 mol s^-1
(ii) L mol^-1 s^-1

Question 12.
How will you account for the acidic nature of carboxylic acids? Compare the relative acidic strengths of: (1½)
(i) F CH₂COOH and ClCH₂COOH
(ii) C₆H₅COOH and p-NO₂C₆H₄COOH

Question 13.
Why is aniline soluble in aqueous HCl? (1½)

Question 14.
Can Gatterman-Koch’s reaction be considered similar to Friedel craft’s aeylation? Discuss. (1½)

Question 15.
Account for the following : (1½)
(i) Aniline does not give Friedel-Crafts reaction.
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) pK_b of methylamine is less that of aniline.

Section – C
Long Answer Type Questions

Question 16.
How will you distinguish between the following pairs of terms: (3)
(i) Hexagonal close-packing and cubic close packing
(ii) Crystal lattic and unit cell
OR
Explain:
(a) Zinc oxide is white but it turns yellow on heating and becomes highly conducting.
(b) CdCl₂ will induce schottky defect if added to AgCl crystal. (3)

Question 17.
Define the term solution. How many types of solutions are formed? Write in brief about each type of solution with an
example. (3)
OR
The depression in the freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly. (3)

Question 18.
(a) What is meant by the following terms? Given an example of the reaction in each case.
(i)Aldol
(ii) Semicarbazone
(b) Complete the following :

OR
Write short notes on :
(a) Cross aldol condensation.
(b) Rosenmund’s reduction
(c) Wolff kishner reduction. (3)

Section – D
Essay Type Questions

Question 19.
(a) Give a separate chemical test to distinguish between the following pairs of compounds : (4)
(i) Ethanol and Phenol
(ii) 2-Pentanol and 3-Pentanol
(b) Explain Kolbe’s reaction with the help of suitable example.
OR
(a) Discuss the acidic dehydration of primary alcohol at 443K
(b) Write Kolbe reaction of phenol.
(c) Write two uses of Methanol.

Question 20.
Explain giving a reason.
(i) Transition metals and many of their compounds show paramangetie behaviour.
(ii) The enthalpies of atomisation of the transitipn metals are high.
(iii) The transition metals generally from coloured compounds.
(iv) Transition metals and their many compounds act as good catalyst. (4)
OR
Explain the following
(a) Europium (II) is more stable than cerium (II)
(b) Zr and Hf exhibit similar properties.
(c) Scandium forms no coloured ions, yet it is regarded as a transition metal. (4)