ISC (Science)
Academic Year: 2022-2023
Date & Time: 27th February 2023, 2:00 pm
Duration: 3h
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- Candidates are allowed an additional 15 minutes for only reading the paper.
- They must NOT start writing during this time.
- This paper is divided into four sections A, B, C and D.
- Answer all questions.
- Section A consists of one question having sub-parts of one mark each.
- Section B consists of ten questions of tuwo marks each.
- Section C consists of seven questions of three marks each and
- Section D consists of three quesfions of five marks each.
- Internal choices have been provided in one question each in Section B, Section C and Section D.
- All working, including rough work, should be done on the same sheet as, and adjacent to the rest of the answer.
- The intended marks for questions or parts of questions are given in brackets [].
- Balanced equations must be given wherever possible and diagrams where they are helpful.
- When solving numerical problems, all essential working must be shown.
- In working out problems, use the following data :
Gas constant R = 1.987 cal deg-1 mol-1 = 8.314 JK-1mol-1 = 0.0821 dm3 atm K-1 mol-1
1 l. 1 atm =1 dm3 atm = 101.3 J.
1 Faraday = 96500 coulombs.
Avogadro's number = 6.023 x 1023
Fill in the blanks by choosing the appropriate words from those given in the brackets:
[stable, low, aldehyde, unstable, 6, 4, ethane, Clemmensen’s, 2, 3, carboxylic acid, high, propane, Rosenmund's]
The primary alcohols are easily oxidised first into ______ and then into ______.
Chapter: [0.141] Carboxylic acids
Fill in the blanks by choosing the appropriate words from those given in the brackets:
[stable, low, aldehyde, unstable, 6, 4, ethane, Clemmensen’s, 2, 3, carboxylic acid, high, propane, Rosenmund's]
The intermediate activated complex in a chemical reaction is highly ______ due to ______ energy.
Chapter: [0.0302] Collision Theory
Fill in the blanks by choosing the appropriate words from those given in the brackets:
[stable, low, aldehyde, unstable, 6, 4, ethane, Clemmensen’s, 2, 3, carboxylic acid, high, propane, Rosenmund's]
The coordination number and oxidation state of the complex K4[Fe(CN6)] are ______ and ______ respectively.
Chapter: [0.07] Coordination Compounds
Propanone on reaction with zinc amalgam in the presence of conc. HCI gives ______ and the reaction is known as ______ reduction.
stable
low
aldehyde
unstable
6
4
ethane
Clemmensen’s
2
3
carboxylic acid
high
propane
Rosenmund's
Chapter: [0.131] Carbonyl compounds
The reaction of a primary amine with chloroform and ethanolic KOH is called ______.
Carbylamine reaction
Kolbe's reaction
Reimer-Tiemann reaction
Wurtz-Fittig reaction
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
Which one of the following statements is true for the galvanic cell?
Electrons flow from the copper electrode to the zinc electrode.
Current flows from the zinc electrode to the copper electrode.
Cations move towards the copper electrode.
Cations move towards zinc electrode.
Chapter: [0.062] Galvanic cells, mechanism of current production in a galvanic cell;
Which one of the following compounds is diamagnetic and colourless?
\[\ce{K2Cr2O7}\]
\[\ce{ZnSO4}\]
\[\ce{KMnO4}\]
\[\ce{Cr2(SO4)3}\]
Chapter: [0.02] States of Matters: Structure and Properties Solid State
For a first order reaction, the half-life period (t1/2) is ______.
proportional to the initial concentration.
inversely proportional to the initial concentration.
proportional to the square root of the initial concentration.
independent of the initial concentration.
Chapter: [0.0301] Order of a reaction
Match the following:
| (i) | Phenol | (a) | Hexane + heptane |
| (ii) | EDTA | (b) | Globular protein |
| (iii) | Ideal solution | (c) | Azo dye |
| (iv) | Insulin | (d) | Hexadentate ligand |
Chapter: [0.12300000000000001] Distinction between primary, secondary and tertiary alcohols
Assertion: If a solution contains both H+ and Na+ ions, the H+ ions are reduced first at cathode.
Reason: Cations with higher E° value are reduced first at cathode.
Both Assertion and reason are true and Reason is the correct explanation for Assertion.
Both Assertion and Reason are true, but Reason is not the correct explanation for Assertion.
Assertion is true but Reason is false.
Assertion is false but Reason is true.
Chapter: [0.052000000000000005] Ionic product of water, pH of solutions and pH indicators
Assertion: Addition of bromine water to 1-butene gives two optical isomers.
Reason: The product formed contains two asymmetric carbon atoms.
Both Assertion and Reason are true, and Reason is the correct explanation for Assertion.
Both Assertion and Reason are true, but Reason is not the correct explanation for Assertion.
Assertion is true but Reason is false.
Assertion is false, but Reason is true.
Chapter: [0.07] Coordination Compounds
Calculate the mass of ascorbic acid (molecular mass = 176 g/mol) that should be dissolved in 155 g of acetic acid to cause a depression of the freezing point by 1.15 K. Assume that ascorbic acid does not dissociate or associate in the solution. (Kf for acetic acid = 3.9 K kg/mol)
Chapter: [0.013000000000000001] Relative molecular mass of non-volatile substances
Give a reason for the following:
Cu+2 salts are paramagnetic, while Cu+ salts are diamagnetic.
Chapter: [0.02] States of Matters: Structure and Properties Solid State
Give a reason for the following:
Mn+2 compounds are more stable than Fe+2 compounds.
Chapter: [0.08] Chemistry of p-Block Elements: Group 16, 17, 18
Give a chemical equation for the following:
Ethyl chloride is treated with aqueous KOH solution.
Chapter: [0.121] Methods of preparation, manufacture, properties and use
Give a chemical equation for the following:
Chlorobenzene is treated with ammonia at 573 K and high pressure.
Chapter: [0.114] Chlorobenzene
State one reason for the following:
Alkylamine is soluble in water, whereas arylamine is insoluble in water.
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
State one reason for the following:
Methylamine is a stronger base than methyl alcohol.
Chapter: [0.121] Methods of preparation, manufacture, properties and use
Calculate the emf of the following cell at 298 K.
\[\ce{Cu/Cu^{2+}_{(0.025 M)}//Ag^+_{(0.005 M)}/Ag}\]
Given `"E"_("Cu"^(2+)//"Cu")^circ` = 0.34 V, `"E"_("Ag"^+//"Ag")^circ` = 0.80 V
1 Faraday = 96500 C mol -1
Chapter: [0.062] Galvanic cells, mechanism of current production in a galvanic cell;
Complete and balance the following chemical equation:
\[\ce{KMnO4 + KI + H2SO4 → }\]_____ + _____ + _____ + ______
Chapter: [0.121] Methods of preparation, manufacture, properties and use
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Complete and balance the following chemical equation:
\[\ce{K2Cr2O7 + H2SO4 + H2S →}\]____ + ____ + ____ + ____
Chapter: [0.121] Methods of preparation, manufacture, properties and use
How will the following be obtained? (Give chemical equation):
Ethanol from Grignard's reagent.
Chapter: [0.142] Acid derivatives
How will the following be obtained? (Give chemical equation):
Diethyl ether from sodium ethoxide.
Chapter: [0.132] Ethers
An organic compound [A] C2H6O, on heating with conc. H2SO4 at 413 K gives a neutral compound [B] C4H10O. Compound [B] on treatment with PCl5 gives a product, which on subsequent treatment with KCN yields compound [C] C3H5N. Compound [C] on hydrolysis gives an acid [D] C3H6O2. Identify the compounds [A], [B], [C] and [D].
Chapter: [0.141] Carboxylic acids [0.142] Acid derivatives
The osmotic pressure of blood at 37°C is 8.21 atm. How much glucose in grams should be used per litre of aqueous solution for an intravenous injection so that it is isotonic with blood? (Molecular wt of glucose = 180 g/mol)
Chapter: [0.013000000000000001] Relative molecular mass of non-volatile substances
An aromatic carboxylic acid [A], which readily sublimes on heating, produces compound [B] on treatment with PCl5, Compound [B], when reduced in the presence of Pd catalyst over BaSO4 poisoned by sulphur in xylene solution, gives compound [C]. When compound [C] is condensed in the presence of alcoholic KCN, it gives compound [D] (Molecular formula of compound [D] is C14H12O2)
Identify the compounds [A], [B], [C] and [D].
Chapter: [0.141] Carboxylic acids
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
Chapter: [0.1] Chemistry of Transition and Inner-Transition Elements: d-Block: 3d, 4d and 5d series f-Block: 4f and 5f series
How would you account for the following?
Transition metals and their compounds act as catalysts.
Chapter: [0.1] Chemistry of Transition and Inner-Transition Elements: d-Block: 3d, 4d and 5d series f-Block: 4f and 5f series
20% of a first-order reaction is completed in five minutes. How much time will the 60% reaction take to complete? Calculate the half-life period (t1/2) for the above reaction.
Chapter: [0.0301] Order of a reaction
Write the balanced chemical equation for the following name reaction:
Sandmeyer's reaction
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
Write the balanced chemical equation for the following name reaction:
Wurtz reaction
Chapter: [0.114] Chlorobenzene
Write the balanced chemical equation for the following name reaction:
Finkelstein reaction
Chapter: [0.115] Preparation, properties, and uses of the following
Give an example of reducing sugar.
Chapter: [0.17] Biomolecules – carbohydrates, proteins, enzymes, vitamins and nucleic acids
Give an example of non-reducing sugar.
Chapter: [0.17] Biomolecules – carbohydrates, proteins, enzymes, vitamins and nucleic acids
What is denaturation of proteins?
Chapter: [0.17] Biomolecules – carbohydrates, proteins, enzymes, vitamins and nucleic acids
Give an example of water soluble vitamin.
Chapter: [0.17] Biomolecules – carbohydrates, proteins, enzymes, vitamins and nucleic acids
Give an example of fat soluble vitamin.
Chapter: [0.17] Biomolecules – carbohydrates, proteins, enzymes, vitamins and nucleic acids
When 2 g of benzoic acid is dissolved in 25 g of benzene, it shows a depression in freezing point equal to 1.62 K. The molal depression constant (Kf) of benzene is 4.9 K kg mol-1, and the molecular weight of benzoic acid is 122 g/mol. What will be the percentage association of the benzoic acid?
(Benzoic acid forms dimers when dissolved in benzene.)
Chapter: [0.013000000000000001] Relative molecular mass of non-volatile substances
Account for the following:
Phenol is a stronger acid than aliphatic alcohol.
Chapter: [0.12300000000000001] Distinction between primary, secondary and tertiary alcohols
Account for the following:
Ethanol gives iodoform reaction whereas methanol does not give iodoform reaction.
Chapter: [0.131] Carbonyl compounds
Account for the following:
Ethers should not be distilled to dryness.
Chapter: [0.132] Ethers
Identify the compounds [A], [B] and [C] in the following reaction:
\[\ce{CH3COOH ->[NH3][\Delta] [A] ->[Br2 + KOH] [B] ->[CHCl3 + NaOH_{(alc)}] [C]}\]
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
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Identify the compounds [A], [B] and [C] in the following reaction:
\[\ce{CH3Br ->[KCN] [A] ->[LiAlH_4] [B] ->[HNO2][273 K] [C]}\]
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
How will the following be converted? (Give chemical equation)
Ethyl bromide to ethyl isocyanide
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
How will the following be converted? (Give chemical equation)
Aniline to benzene diazonium chloride.
Chapter: [0.15] Cyanides, Isocyanides, Nitro compounds, Amines and Diazonium Salt
How will the following be converted? (Give chemical equation)
Benzene diazonium chloride to phenol
Chapter: [0.12300000000000001] Distinction between primary, secondary and tertiary alcohols
A first-order reaction is 50% completed in 40 minutes at 300 K and in 20 minutes at 320 K. Calculate the activation energy of the reaction. (Given : log 2 = 0·3010, log 4 = 0·6021, R = 8·314 JK–1 mol–1)
Chapter: [0.0305] The concept of energy
Write a chemical equation to illustrate the following name reaction:
Cannizzaro’s reaction.
Chapter: [0.131] Carbonyl compounds
Write a chemical equation to illustrate the following name reaction:
HVZ reaction
Chapter: [0.141] Carboxylic acids
Write a chemical equation to illustrate the following name reaction:
Aldol condensation.
Chapter: [0.131] Carbonyl compounds
How will the following be converted? (Give chemical equation)
Acetaldehyde to acetone
Chapter: [0.131] Carbonyl compounds
How will you bring about the following conversion? (Give equation).
Formaldehyde to urotropine
Chapter: [0.131] Carbonyl compounds
Name the type of isomerism exhibited by the following pair of compound:
\[\ce{[Co(NH3)5 [ONO]Cl2 and [Co(NH3)5(NO2)]Cl2}\]
Chapter: [0.07] Coordination Compounds
Name the type of isomerism exhibited by the following pair of compound:
\[\ce{[Cr(H2O)5Cl]Cl2H2O and [Cr(H2O)4Cl2]Cl {.} 2H2O}\]
Chapter: [0.07] Coordination Compounds
Name the type of isomerism exhibited by the following pair of compound:
\[\ce{[Pt(NH3)4Cl2]Br2 and [Pt(NH3)4 Br2]Cl2}\]
Chapter: [0.07] Coordination Compounds
Write the IUPAC name of the following complex:
\[\ce{[Co(NH3)4(H2O)2]Cl3}\]
Chapter: [0.07] Coordination Compounds
Write the IUPAC name of the following complex:
\[\ce{K2[Ni(CN4)]}\]
Chapter: [0.07] Coordination Compounds
The specific conductance of 2.5 × 10-4 M formic acid is 5.25 × 10-5 ohm-1 cm-1. Calculate its molar conductivity and degree of dissociation.
Given `λ°_("H"^+)` = 349.5 ohm-1 cm2 mol-1 and
`λ°_("HCOO"^-) = 50.5 " ohm"^-1 "cm"^2 "mol"^-1`
Chapter: [0.064] Electrolytic conductance
Calculate the time taken to deposit 1.27 g at copper at cathode when a current of 2 amp. is passed through the solution of CuSO4.
(Atomic weight of Cu = 63.5 gmol-1)
Chapter: [0.061] Faraday’s laws of Electrolysis, Coulometer
The resistance of a conductivity cell with a 0.1 M KCl solution is 200 ohm. When the same cell is filled with a 0.02 M NaCl solution, the resistance is 1100 ohm. If the conductivity of 0.1 M KCl solution is 0.0129 ohm-1 cm-1, calculate the cell constant and molar conductivity of 0.02 M NaCl solution.
Chapter: [0.064] Electrolytic conductance
The emf \[\ce{E^\circ_\text{cell}}\] of the following reaction is 0.89 V.
\[\ce{3Sn^{4+} + 2Cr -> 3Sn^{2+} + 2Cr^{1+}}\]
Calculate the value of ΔG° for the reaction. Predict whether the above reaction will be spontaneous or not.
Chapter: [0.062] Galvanic cells, mechanism of current production in a galvanic cell;
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