d- block elements

The elements whose atoms in ground state or ions in their common oxidation states have partly filled d-orbitals are called d-block elements. In these elements the last electron enters the (n-1) orbital.

These elements are called as transition elements because their properties are transitional between highly reactive metallic elements of S block and largely covalent character of p-block elements. These elements also have variable oxidation states.

First transition series : 3d series – 10 elements from Scandium (Z=21) to Zinc (Z=30).

Second transition series : 4d series – 10 elements

from Yttrium(Z=39) to Cadmium(Z=48)

Third transition series : 5d series – 10 elements from Lanthanum(Z=57), then Hafnium (Z=72) to Mercury (Z= 80)

Fourth transition series: 6d series –Actinium(Z=89) as first member rest are synthetic elements from rutherfordium (Z=104) onwards upto Z=112.

Properties of Transition elements:

(a) Electronic configuration: General electronic configuration of d-block elements is [noble gas](n-1)d1-10n1-2

Electronic configuration of Chromium is 1s22s22p63s23p63d54s1

Because half filledstate is extra stable.Electronic configuration of Copper is 1s22s22p63s23p63d104s1

Because of fully filled state it is extra stable.

(b) Atomic Size : In the transition series the size of the atom decreases first then remains constant and then increases slightly.Explanation:

In the beginning the decrease in size is due to increase in effective nuclear charge with increase in atomic number.

In the middle of the series the atomic number remains constant because, with increase in number of electrons in (n-1) d subshell, the screening effect of inner electrons on electrons present in the outer shell(ns) increases which neutralizes the effect of increased nuclear charge.

Towards the end of the series, atomic size increases. This is because of the inter electronic repulsion in (n-1)d orbital due to pairing of electrons. This repulsion in electron causes expansion of electron cloud, hence the increase in atomic size.

(c) Oxidation state : Transition elements can have different oxidation states. Most of the elements show variable oxidation states. The reason being when transition metals form compounds, the electrons present in ns and (n-1)d orbitals can participate in bonding due to almost similar energies.

Lower oxidation state is exhibited if ns electron participate. Eg.- Mn2+. Higher oxidation state is exhibited if both ns and (n-1)d electrons participate. Eg- Mn7+

Mn7+ in KMnO4, Mn2+ in MnSO4. Transition metal ions form ionic compounds in their lower oxidation state like +2, +3.

Eg- Cu(II)SO4, Fe(III)Cl3. Transition metals form covalent compounds in their higher oxidation state like Mn7+.

Bonds between Manganese and oxygen are covalent. Transition metals can form zero valent metal compounds also. Eg. Ni(CO)4.

(d) Colour of transition metal ions : Transition metal ions are coloured in their solid state or in aqueous solutions are coloured.

Because they absorb particular radiation from white light(visible light) and transmit remaining light(colours) which is called as complementary colour to absorbed colour.

Eg.- CuSO4 solution is blue because it absorbs red colour and transmits blue. The colour depends on the number of unpaired electrons present. The unpaired electrons

present in the d-orbitals of transition metal ion undergo d-d transition by absorbing the energy of certain electromagnetic radiation.

In transition metal atom or ion, all 5 d orbitals have same energy (degerate) but when water (ligand) or any other ligand molecules approach them these 5 orbitals split into two sets having different energies – 3 orbitals having lower energy called t2g and 2 orbitals having slightly higher energy called eg. This is called as crystal field splitting. The electron present in the lower orbitals can jump to higher level just by absorbing small amount of energy which is available in radiation present in white light. Thus, when white light falls on transition metal compounds, some radiations are absorbed and complementary colour is transmitted which gives colour to the soloution.Difference between eg and t2gorbitals is ∆E.∆E = hv. This is called as crystal field splitting energy.

{ } eg – dx – y, dz

↕ { } t2g – dxy, dyz, dxz.

Few questions: 1. Indicate which ion is coloured : Cu+, Ti4+,Ni2+,Sc3+.

Ans: Cu+, Ti4+,Sc3+ have no unpaired electrons. Hence they are not coloured. Ni2+ has two unpaired electrons. It is coloured because the unpaired electrons undergo d-d transition by absorbing energy.

2. Though Zinc is considered as a transition metal, its salt solutions are colourless. In salt solutions, zinc is in its +2 oxidation state. In this state it has no unpaired electrons and hence in solution remains colourless.

(e) Magnetic properties : Transition metals and their compounds have magnetic properties. Most of their compounds

are paramagnetic in nature because of unpaired electrons present in their d-orbitals. Paramagnetic – These are substances which have unpaired electrons and are attracted

towards the magnetic field. Diamagnetic – These are substances which have paired electrons and are repelled by a

magnetic field. The magnetic moment of transition metal ions are calculated using formula:

µ = √n(n+2) B.Mwhere µ is the magnetic moment and n is the number of unpaired electrons.

Ferromagnetic – These are substances which are strongly attracted by magnetic fields. Some paramagnetic substances become permanent magnet under the influence of applied magnetic field, ie.., once magnetized they don’t lose their magnetic character even if magnetic field is removed. Such substances are called ferromagnetic substances. Eg- Fe, Ni, Co.

Except Zn, Cd and Hg all the remaining 3d series of elements contain unpaired electrons and are paramagnetic.

When iron is heated to 7680C, it loses its ferromagnetic property. This temperature is called as curie point.

Few questions: 1. Out of Cobalt and Zinc salts which are attracted in a magnetic field.

2. Explain diamagnetic behaviour of Zinc.3. Explain why Cu2+ is paramagnetic while Cu+ is diamagnetic.

(f) Formation of complexes : Transition metals have tendency to combine with neutral molecules or ions called

ligands and form co-ordinate compounds or complexes. This property is due to empty d- orbitals available in transition elements. Due to which they form co-ordinate bonds with ligands.Eg- Cuprammonium sulphate – [Cu(NH3)4]SO4

Potassium ferrocyanide – K4[Fe(CN)6] Another important factor responsible for formation of complexes is high polarising power

due to small size and high positive charge.

Charge Polarising power = Size

Stability of complexes increases with increase in atomic number of metal ion and complexes of metal ion having higher oxidation state then lower oxidation state.

(g) Catalytic properties : Many transition elements and their compounds act as catalyst in different process.

(1) Iron and molybdenum in Haber process.(2) V2O5 in contact process to convert SO2 to SO3.(3) Ni catalyst in hydrogenation of oils and ghee.(4) Pt wire gauze in manufacture of HNO3 in ostwald’s process.

Reasons: (1)Transition metals can exhibit in variable oxidation states due to unpaired electron. So they can form number of intermediates with lower energy of activation by following different paths which convert into product finally. (2) They provide large surface area. The reacting molecules are readily adsorbed on the surface and react readily to form products.

INORGANIC CHEMISTRY

METALLURGY

Part A questions:

1. Partition coefficient of iodine in carbon tetrachloride and water is 85. What does it mean.2. ∆Go values for the formation of alumina and chromium sesquioxide are -827kJ

and -540kJ. Which of the two oxides is more stable. 3. Name the reducing agent in the extraction of iron.4. In the parke’s process, molten zinc is mixed with molten argentiferrous lead. Why?5. What is the partition coeffiecient of silver in a mixture of molten zinc and molten lead?6. What is the role of limestone in the extraction of iron from haematite ?7. Name the pure form of iron.8. Out of carbon and zinc, which is a stronger reducing agent.9. What is argentiferrous lead?10. State Nernst distribution law.11. Define Partition coefficient.12. What is pig iron?13. At the top of the furnace which reducing agent reduces iron oxide to iron.

Part B questions:

1. Explain the questions with the help of Ellingham diagrams: (2 mark each)a) At low temperatures carbon monoxide is a better reducing agent than carbon.

b) Aluminum is used as a reducing agent to reduce chromic oxide.c) Aluminum can reduce MgO at a higher temperature.d) Mercuric oxide can be thermally decomposed at relatively low temperature.e) Silver oxide readily decomposes above 300oC.f) Though carbon can reduce chromic oxide to chromium at temperatures above 1500oC, still it is

not used to as a reducing agent.g) Carbon monoxide is a reducing agent for the extraction of iron from haematite.h) Only at high temperatures carbon can reduce metal oxides to metal.i) Reduction of zinc oxide to zinc.

2. Describe the reactions that occur in the blast furnace during the extraction of iron.

Part C questions:

1. Describe the reactions that occurs during the extraction of cast iron in furnace at:a) 600oCb) 900-1000oCc) 1500oCd) 1200oC

2. Outline the procedure of desilverisation of lead by parke’s process.3. How is cast iron manufactured from heamatite using blast furnace?

INDUSTRIALLY IMPORTANT COMPOUNDS

Part A questions:

1. H2S gas is not dried using concentrated sulphuric acid. Why?2. Name the gas liberated at cathode when caustic soda is manufactured using Nelson’s cell.3. Name the compound formed when potassium dichromate reacts with KOH.4. What happens on acidifying a solution of potassium chromate using sulphuric

acid ?5. Name the catalyst used in contact process.6. During electrolysis of brine H+ ions get discharged in preference of sodium ions. Give the reason.7. How is sodium hydroxide purified?8. What is the function of asbestos lining in the Nelson’s cell?9. What is the composition of soda lime?10. Write the formula of oil of vitriol.11. What is meant by liquor ammonia ?12. What is brine?13. In contact process why reactant gases are purified before passing them over the catalyst.14. Sulphur dioxide turns acidified potassium dichromate paper green. Why?

Part B questions: (any chemical reaction in the chapter can be asked for two marks)

1. Justify that concentrated sulphuric acid is a good dehydrating agent with an example of an equation.2. What is the action of potassium hydroxide on potassium dichromate?3. How does concentrated sulphuric acid react with a mixture of sodium chloride and potassium

dichromate crystals?

Part C questions:

1. Describe the manufacture of NaOH using Nelson’s cell.2. How is potassium dichromate manufactured from chromite ore?3. Describe the contact process for the manufacture of sulphuric acid.4. How is ammonia manufactured by Haber’s process?

NOBLE GASES

Part A questions

1. Name the noble gas compound which was isolated by Bartlett.2. What is the source of noble gases.3. Which is the most abundant rare gas.4. How is radon formed?5. What is the half life of radon? (3.8 days)6. Name the noble gas compound isolated by Bartlett.

Part B questions:

1. How is the mixture of noble gases separated by Dewar’s Charcoal adsorption method?2. How are noble gases isolated from air by Ramsay and Rayleigh method?

d- block elements

1. Give the general electronic configuration of d-block elements.2. Why is electronic configuration of chromium 3d54s1 and not 3d44s2 ?3. Why Fe3+ ion is more stable than Fe2+ ion?4. What is the highest oxidation state shown by an element in the 3d-block? (+7, Manganese)5. Name a compound in which manganese shows an oxidation state fo +7. (KMnO4).6. What are the factors on which the colours of transition metal ions depend?7. Though Zinc is considered as a transition metal, its salt solutions are colourless.8. Copper ( II) salts solutions are blue in colour and copper(I) salts are colourless.9. What are diamagnetic and paramagnetic materials?10. What are ferromagnetic materials?11. Give the reason for catalytic behaviour of the 3d-block elements.12. Among Sc3+ ( atomic number = 21) and Cr3+ ( atomic number = 24), which ion is coloured and why?13. Why do 3d elements exhibit variable oxidation state?14. Zn2+ ions are diamagnetic. Explain.

Coordination compounds

Part A questions:

1. Give the formula of potassium hexacyanoferrate.2. What type of ligands satisfy the primary valencies of metal ions?3. Give an example of a complex where a ligand satisfies both the primary and secondary valencies of

the metal ion.4. Give the example of a coordition compound where the oxidation state of the central metal atom is

zero.5. Give an example of a complex compound which

(1) obeys EAN rule (2) does not obey EAN rule.6. What type of hybridisation leads to the formation of planar structure.7. Give an example for a complex which is (a) diamagnetic (b) paramagnetic.8. How many unpaired electrons are present in the following complexes:

(a) Ni(CO) (b) [Cu(NH3)4]SO4 (c) K4[Fe(CN)6]9. Give an example of complex cation / complex anion.10. Give the IUPAC name of potassium ferricyanide.11. Give an example of inner / outer complex.12. IUPAC names of coordination compounds. Examples given in book.

Part B questions:

1. Explain monodentate / bidentate / tridentate / polydentate ligands with an example.2. Explain linkage/ hydrate / ionisation isomerim with an example.3. Explain cationic complex / anionic complex / neutral complex with an example.4. Calculate EAN of K4[Fe(CN)6] / [Ni(CO)4] / [Cu(NH3)4]SO4.

5. What is EDTA?

Part C questions:

1. Write the assumptions of Werner’s theory. Explain the structure of CoCl3.5NH3 on the basis of Werner’s theory.

2. Explain the salient features of Valence bond theory.3. On the basis of Valence bond theory, explain the hybridisation, electron arrangement, geometrical

shape and magnetic properties of K4[Fe(CN)6] / [Ni(CO)4] / [Cu(NH3)4]SO4.

Chemical Bonding

Part A questions:

1. Write the electronic configuration of lithium / hydrogen / oxygen molecule.2. Two atomic orbitals undergo asymmetric combination by LCAO. What type of molecular orbital is

formed?3. What is the significance of Ψ and Ψ2.4. How are molecular orbitals formed?5. Between σ1s and σ*1s which orbital is of higher energy.6. Define the term bond order.7. Name the metal which exhibits photoelectric effect.

Part B questions:

1. Sketch the formation of molecular orbitals formed by the linear combination of two s orbitals.2. Differentiate between bonding molecular orbital and antibonding molecular orbital.3. Explain the salient features of electron sea model theory.4. How does electron gas theory explain the following properties: Bright metallic luster/ Opaque nature

/ Thermal conductivity / Electrical conductivity / Malleability and ductility / Thermo-ionic emission and photoelectric effect.

5. Give reason:(1) Alkali metals are soft.(2) Mercury is a liquid metal.(3) Transition metals have high density.

6. Helium molecule does not exist. Give reason.7. Give the energy level diagram of lithium / hydrogen molecule.

Part C questions:

1. Explain the salient features of molecular orbital theory.2. Oxygen is paramagnetic in nature. Explain with the help of molecular orbital theory.

NUMERICALS

CHEMICAL KINETICS

1) For a first order reaction A→ products, the initial concentration of A was found to be 9 mole / dm-3. After 30 min the concentration was reduced to 4.5 mole / dm-3. Calculate the time required for 80% completion of the reaction.

(70min)

2) Half life of a reactionA→ products is 3.33 hr at 298 K. Calculate the rate constant for the reaction. If the reaction is started from one mole of A what amount of A would remain unreacted at the end of 9hr.

(0.1538mole)

3) A first order reaction is 50% complete in 80 min. Calculate the rate constant for the reaction. (8.66 x10-3 /min)

4) Rate constant for a first order reaction is 1.23 x 10-2 /s. Calculate the half life of the reaction. (563.4s)

5) Calculate the rate constant for the first order reaction in which 75% of the reaction is completed in 30 min. ( 0.0462/min)

6) Calculate the time required for the initial concentration of 2.0 mol dm-3.to get reduced to 1.2 mol dm-3 .Given: k = 0.009 /min. (56.8min)

7) Rate constant of a first order reaction is 2.3 x10-4/s . Calculate the time taken for the completion of 2/3 of the reaction. (4776 s)

8) A first reaction is 40% completed in 50 min. What is the time required for 90%of the reaction to complete? (225min)

9) The rate of a particular reaction doubles when temperature changes from 20 0 to

50 0C. Calculate the energy of activation for the reaction. (28.82 kJ/mol)

10) For a reaction the activation energy is zero. What is the value of rate constant at 300K if k = 1.6 x 106 /s at 280 K. (1.6 x 106 /s)

THEROY OF DILUTE SOLUTIONS

1) The vapour pressure of pure benzene at a certain temperature is 200 mm/Hg. At the same temperature , the vapour pressure of a solution containing 2 g of a non volatile solute in 78 g of benzene is 195 mm/Hg. What is the molar mass of the solute? (80 g/mol)

2) 3 g of urea is dissolved in 9 g of water. Calculate the relative lowering in vapour pressure. (0.0909)

3) A current of dry air was passed through a solution containing 5.4g of an aromatic compound in 61.2g of diethyl ether and through the solvent. The loss in the mass of solution bulb was 0.708g and that of the solvent bulb was 0.035g. Calculate the molar mass of the aromatic compound. ( Mol mass of diethyl ether =74 g/ mol)

(138.61g/mol)

4) 18.2g of urea is dissolved in 100g of water at 50 0C. The relative lowering of vapour pressure is 660 Pa. The vapour pressure of pure water at the same temperature is 12260 Pa. Calculate the molar mass of urea (60.85g/mol)

5) Vapour pressure of pure water at 298K is 303 kPa. Calculate the relative lowering in vapour pressure of an aqueous solution containing 20g of glucose dissolved in 90g of water at 298 K. Mol mass of glucose =180g/mol. (0.02222)

CHEMICAL THERMODYNAMICS-2

1) For a process H2O(l)═ H2O (g); ΔH0 =44 kJ and ΔS0 =118.8x10-3kJ/K. Calculate the temperature at which water vapour and water are in equilibrium. (370K)

2) The standard free energy change for a reaction is -115 kJ/mol at 298 K. Calculate the equilibrium constant Kp. (1.428x 1020)

3) The standard free energy change for a reaction is 62 kJ/mol. Calculate the equilibrium constant at 300K. (1.606x10-11)

4) The value of standard free energy change for ammonia at 298K is -16.6 kJ/mol. Calculate equilibrium constant for the reaction. (8.114x102)

5) The value of equilibrium constant for a reaction is found to be 1.06x105 at 298K. Calculate ΔG0 for the reaction at the same temperature. (-28.674 kJ/mol)

6) Equilibrium constant for a reaction at 300K is 3.5x10-4. Calculate the standard free energy change . Under these conditions is the reaction spontaneous?

Give reason. (19851.18 J/mol)

Numericals

Elecrochemistry

Faraday’s laws of electrolysis1) Calculate the time required to liberate 56 cm3 of hydrogen at S.T.P. if 5 amperes of current flows. (96.5s)

2) Molten AlCl3 is electrolysed using a current 0.5 ampere to produce 27 g of Al. a)calculate number of Faradays of electricity used b)number of electrons produced. (3, 1.8066 X 10 24)

3) When the same amount of electricity is passed in to AgNO3 and HCl , 1.08g Ag is obtained in the first case. Calculate the volume of H2 evolved at S.T.P. in the second case. (112 cm3)

Ostwald ‘s dilution law4) Calculate the degree of dissociation of 0.1M acetic acid.(Ka=1.8x10-5)

5) Calculate the dissociation constant of 1/32 acetic acid if the degree of dissociation at 298K is 0.0236.(1.74x10-5)

6) Calculate the hydrogen ion concentration of 0.1N acetic acid . (Ka=1.8x10-5) (1.34x10-3M)

7) Calculate the dissociation constant of 0.01M acetic acid if the degree of dissociation at 250C is 0.02. Also calculate hydrogen ion concentration. (4x10-6, 2x10-4M )

pH and pOH

8) Calculate the pH of 0.001M HCl. (3).

9) Which of these solutions has higher pH value? a)0.1M NaOH b) 0.01M KOH.

10) What is pH of N/100 HCl solution?

11) Calculate the [H+] of a solution with pH 4.82 . (1.512x10-5)

12) 40g of NaOH is dissolved in 10 litre of the solution. What is the pH of the solution? (10)

13) Calculate the pH of 0.5M H2SO4 solution. (0)

14) Calculate the [H+] concentration of blood (pH=7.3) (5.02x10-7)

pH of buffer solutions numerical on Henderson equations15) A buffer solution contains 0.1M NH4OH and 0.15M NH4Cl. Calculate the pOH of the buffer solution. (Kb=1.8x10-5) (4.921)

16) Calculate the mass of sodium acetate that should be dissolved in 500 cm3 of 0.02M acetic acid to prepare a solution of pH 4.6. (Ka=1.8x10-5) (0.587g)

17) An acidic buffer was prepared by adding 0.03Msodium acetate to 1dm3of 0.015M acetic acid. Calculate the pH of the buffer solution. (Ka=1.8x10-5) (5.0457)

18) Calculate the number of moles of sodium formate to be dissolved in one dm3 of 0.2M formic acid to give a solution of pH 5 (K afor formic acid=1.77x10-4)( 3.54 mol/dm3)

19) 0.08 mole of acetic acid and 0.12 mole of sodium acetate are mixed in 1 dm3 solution. Calculate the pH of resulting buffer solution. (Ka=1.8x10-5) (4.921)

20) A buffer solution contains 0.4 moles of NH4OH and 0.8 moles of NH4Cl per dm3 of the solution. Calculate the pH of the solution. (Kb=1.8x10-5) (8.954)

Solubility product21) The solubility product of lead iodide is 1.3x10-8mol3dm-9at 298 K. What is its solubility? (6.875x10-3 mol dm-3)

22) The solubility product of barium sulphate is 1.2 x 10-10 mol2 dm-6 .Calculate the solubility of barium sulphate in water. (1.095 x10-5 mol dm-3)

23) The solubility of AgCl at 293 K is 0.0016 g dm-3. Calculate its solubility product at the same temperature. ( molecular mass of AgCl is 143.5) (1.243 x 10-10 mol2 dm-6)

EMF cells24) Calculate the standard reduction potentials of Cd2+ /Cd electrode for the cell:

Zn(s)/Zn 2+ (1M) II Cd2+(1M)/Cd(s) Given ;E 0cell=0.36V and E 0

Zn 2+/Zn= -0.76V (-0.40V)

25) SRP of Mg is -2.37V and SRP of ZN is -0.76V. Calculate the EMF of the cell formed by combining Mg and Zn electrodes. Write the cell reaction and give the symbolic representation of the cell.

26) Calculate the EMF of the cell prepared by combining Zn/1M ZnSO4and Cu/1M CuSO4 at 298K.(Given E0Zn =-0.76V;

E0Cu=+0.34V). (1.1V)

27) Calculate the reduction potential for the following half cell reaction at 298K

Ag+(aq) + e_ →Ag(s) Given ;[Ag+]=0.1M and E0 =+0.80V. (0.741V)

28) Calculate the electrode potential of Cu electrode dipped in 0.1M CuSO4 at 250C ( E0Cu=+0.34V)

(0.31V)

Physical Chemistry

CHEMICAL KINETICS

Part A

1. Define rate of a reaction2. Give the unit of rate of reaction.3. Define order of a reaction.4. Define half life period.5. How is half life related to order of a reaction?6. How does rate constant vary for a first order reaction varies with temperature?7. Define threshold energy8. What is temperature coefficient of a reaction?9. Write Arrhenius equation10. Define threshold energy.

Part B

1. Explain Pseudo first order reaction with an example.2. Velocity constant of a reaction at 290K is 3.2×10-3 .What is the value of3. rate constant at 300K. (Ea is 52kJmol-1)4. Explain Ostwalds isolation method for the determination of order of a reaction.

5. Explain graphical method to determine order of a reaction. 6. A first order reaction is 50% complete in 60 min. Calculate the rate constant 7. for the reaction.8. What is zero order reaction give an example?

Part C

1. Derive an expression for the velocity constant of a first order reaction2. Show that half life of a first order reaction is independent of the3. initial concentration.4. Calculate the time required for the initial conc. of 2.0 mol/dm3 to get reduced to 5. 1.2 mol/dm3. Given rate constant =0.009min-1

6. Calculate the rate constant for a first order reaction in which 75% of the reaction 7. is completed in 30 min.8. A first order reaction is 75 % complete in 70 min. Find the half life of the reaction.9. A first order reaction is 87.5% complete in 120min. Calculate its half life.

ELECTROCHEMISTRTY

Part A

1. What is [H+] of a neutral solution at 250 C?

2. What is e.m.f of S.H.E?

3. What is the pH of 0.001M nitric acid solution?

4. What is the conjugate acid of S2-, HCO3- ,NH2

-,HSO-4,Cl-?

5. What is the conjugate base of NH+4, OH-?

6. What is the unit of Molar conductance/ specific conductance?

7. What is hydronium ion?

8. Define specific conductance/Molar condutance.

9. How are molar and specific conductance related?

Part B

10 . Explain common ion effect with an example.

11. Account for the fact that water can act both as an acid and a base.

12. Calculate the pH of 0.005 M NH4OH solution. The dissociation constant is

1.8×10-5 at 298 K.

13. The solubility product of PbCl2 is 2.5 ×10-3 at 25˚C. Calculate its solubility.

14. State Faradays I & II laws of electrolysis.

15. Write Nernst equation and explain the terms.

16 .Give reason: On passing H2S in the presence of dil HCl, IInd group basic radicals

is precipitated as their sulphides but not IV group basic radicals.

17. Calculate the degree of dissociation of 0.1M solution of acetic acid.Given

Ka is 1.8×10-5.

18. Suggest any 2 two methods of preventing corrosion of metals.

19. Calculate the electrode potential of copper electrode dipped in 0.1 M CuSO4 at

25˚C (E˚cu =0.34)

20. Calculate the e.m.f of a cell consisting of standard electrodes of two metals

are -2.38 volts and -0.76 volts.

21. Explain amphoteric property of water.

22. Write the factors affecting electrode potential.

23. 8g NaOH is dissolved in 20dm3 of a solution. Calculate the pH.

Part C

24. Give the postulates of Arrhenius theory of electrolytic dissociation.

25. Corrosion is an electrochemical phenomenon.

26. Explain the buffer action of an acidic buffer.

27. Explain the construction and working of Daniel cell.

28. With a neat labeled diagram explain the construction and working of S.H.E.

29. A buffer solution of pH 9 is to be prepared by mixing NH4Cl and NH4OH.

Calculate the number of moles of NH4Cl should be added to 1 litre of 1.0 M

NH4OH solution. Kb=1.8×10-5.

30. In a voltaic cell, the cell reaction is Mg + 2Ag+→ Mg2+ + 2Ag. Represent the

cells using symbols, write the electrode reactions.

CHEMICAL THERMODYNAMICS.

1. State second law of thermodynamics.2. What is the SI unit of entropy?

3. What is change in entropy when a liquid is converted to vapour?4. How does entropy vary in a spontaneous process?5. Write Gibbs equation and explain the terms.6. If ΔH˚ is negative and ΔS˚ is positive .Under what conditions the reaction would be spontaneous?7. The value of equilibrium Kp for a reaction is found to be 1.06×105 at 298K.Calculate ΔG˚ of the reaction at the

same temperature. 8. The standard free energy change for a reaction is 62 kJ/mol.Calculate the equilibrium constant at 300K.9. If ΔH˚ is positive and ΔS˚ is positive .Under what conditions the reaction would be spontaneous?

Theory of dilute solutions

Part A

1. Write Van’t Hoff’s equation for osmotic pressure.2. State Raoult’s law for solution containing volatile liquid mixture.3. Give an example for a synthetic semipermeable membrane.4. Give any two differences between ideal and nonideal solution.5. Sea water freezes below 273K.Why?6. Define molal elevation constant.7. ExplainVan’t Hoff theory of dilute solutions.8. What happens to the vapour pressure of a solvent when a non-volatile solute is dissolved in it?9. Define osmotic pressure.10. What happens to the vapour pressure of a liquid on heating? 11. Give an example of a solution showing positive deviation from Raoult’s law

Part B

12. 6 g of urea is dissolved in 18 g of water. Calculate relative lowering of vapour pressure.13. Why is the osmotic pressure of sodium chloride solution higher than glucose solution?

Part C

14. The vapour pressure of pure benzene at a certain temperature is 200mm of mercury at the same temperature the vapour presssure of solution containing 2g of a non volatile, non electrolytic solid in 78g of benzene is 195mm of mercury. What is the molecular mass of the solid.

15. How is molecular mass of a non-volatile solute determined by Ostwald-Walker’s dynamic method?

COLLOIDS

Part A

1.What is an emulsion?

2.What is peptisation?

3.Between AlCl3 and NaCl whict one is required in minimum concentration to coagulate gold sol.

4.Give an example for a negatively charged colloid.

Part B.

5.What is Brownian movement,How is it caused?

6.How is a colloid purified by dialysis.

7.What is electrophoresis?

8.Describe bredigs electric arc method for preparing gold sol.

9.State the dispersion medium and dispersed phase in an a) aerosol b) sol

10.Give any 2 differences beween lyophillic ann lyophobic sol.

11.Write a note on tyndall effect.

12.State Hardy Schulze rule.Give example.

1. Define gold number .Why is gelatin added to gold sol?2. Give two applications of colloid

………………………….

3-4 MARK QUESTIONS

INORGANIC CHEMISTRY

1. How is Sodium hydroxide manufactured by Nelson’s process ? (4 Marks)2. Explain the manufacture of ammonia by Haber’s process . (3)3. Explain the manufacture of sulphuric acid by contact process. (4)4. How is potassium dichromate manufactured from chromite ore? (4)5. How is a mixture of rare gas isolated from air by Ramsay and Rayleigh’s method ? (2)6. How are rare gases seperated by Dewar’s charcoal adsorption method? (3)7. Write the salient features of valence bond theory. (4)8. Write the assumptions of Werner’s theory. Explain the structure of CoCl3.5NH3 on the basis of Werner’s theory.

(4)9. Explain hybridisation, electronic structure, geometrical shape and magnetic behaviour of

(a) Cuprammonium ion(b) Ferrocyanide ion(c) Nickel tetracarbonyl (4 marks each)

10. Explain the salient features of molecular orbital theory. (4)11. Explain the energy level diagram, bond order and magnetic property of the following molecules:

(a) H2 (b) He2 (c) Li2 (d) O2 (2 or 3 each)12. Sketch the shape of sigma bonding and antibonding molecular orbitals when s-atomic orbital overlap.13. How are the molecular orbitals formed by the linear combination of atomic orbitals. 14. Explain electron gas theory of metallic bond. (3) 15. Explain the extraction of iron from haematite in a blast furnace. (4)16. Explain with the principle, the desilverisation of Lead by Parke’s process. (3)17. Give reason :- (2 to 3 marks each)

(a) Mercuric oxide and silver oxide readily decomposes above 300oC.(b) Aluminium is used as a reducing agent to reduce chromic oxide to chromium.(c) Coke is used as a reducing agent for zinc.(d) Though carbon can reduce chromic oxide to chromium at temperatures above

1500oC, still it is not used as a reducing agent. Why ?(e) Carbon monoxide is a reducing agent for the extraction of iron from haematite.

18. Explain the following with an example: (2 each)(a) Hydrate isomerism

(b) Linkage isomerism(c) Ionisation isomerism

PHYSICAL CHEMISTRY

1. Derive an expression for the velocity constant (rate constant) of a first order reaction. (4)2. Describe Arrhenium theory of electrolytic dissociation. (4)3. Mention the merits and demerits of Arrhenius theory of electrolytic dissociation. (3 each)4. Derive Henderson’s equation for the pH of an acidic buffer solution. (4)5. Derive Henderson’s equation for the pOH of a basic buffer solution (4)6. How is Daniel cell constructed ? Write cell reactions along with the equation for the

Calculation of EMF of the cell. (3)7. With a labelled diagram explain the construction and working of a standard hydrogen electrode. (3) (write

construction, working, cell representation, diagram and equation)8. Explain the buffer action of a basic buffer solution made of NH4OH and NH4Cl. (3)9. Explain the buffer action of a acidic buffer solution. (3)10. Explain common ion effect with an example. (2)11. How is molecular mass of a non-volatile substance determined by ostwald – walker’s

Dynamic method ? (4) 12. Write a short note on Pseudo first order reaction.(pseudo unimolecular) with an example.13. Write a note on Ostwald’s isolation method. (2)14. How is gold sol prepared by Bredig’s arc method? (3)15. Define a. Peptisation, electrophorsis, gold number, brownian movement.

ORGANIC CHEMISTRY

1. Explain Baeyer’s strain theory. (3)

2. Explain Sachse-Mohr theory of Stainless rings. (3)

3. Calculate angle of strain in cyclopropane, cyclobutane and cylcopentane. (2 each)

4. Elucidate the stucture of benzene. (4)

5. Discuss the molecular orbital picture of benzene showing the molecular orbitals involved in theformation of sigma and pi bonds. (4)

6. Explain the mechanism of (a) Chlorination of benzene(b) Nitration of benzene(c) Sulphonation of benzene(d) Friedal crafts alkylation(e) Friedal crafts acylation. (3 each)

7. Explain SN1 mechanism with a example / Explain the mechanism of hydrolysis of ter-butyl bromide.

8. Explain SN2 mechanism with a example. (3)

9. How is phenol isolated from coal tar? (3)

10. How is phenol obtained by cumene process? (2)

11. Explain geometric isomerism and the conditions for geometric isomerism. (3)

12. Explain Reimer tiemann reaction. (3)(or) How is phenol converted to salicylic acid?(or) How is phenol converted to Salicyaldehyde?

13. Explain the mechanism of Cannizaro reaction. (3 or 4)(or) What happens when an aldehyde without an alpha hydrogen is treated with a strong alkali?(or) What happens when benzaldehyde is treated with concentrated alkali?

14. Explain Aldol condensation. (2)(or) what happens when aldehyde is treated with a dilute solution of alkali ?

15. Elucidate the open chain structure of glucose.

16. How are the following conversions carried out? ( a few examples)(a) Isopropyl chloride to propane (haloalkane to alkane – reduction)(b) Isopropyl chloride to propene (Haloalkane to alkene -dehydrohalogenation) (c) Chloroethane to ethyl alcohol (Haloalkane to alcohol -treating with aqueous KOH) (d) Chloroethane to propanenitrile (Haloalkane to alkanenitrile- treating with KCN)(e) Chloropropane to propyl isocyanide (Haloalkane to alkyl cabylamine or alkyl isocyanide-treating with

AgCN)(f) Preparation of grignard reagent.(g) Bromoethane to butane (Wurtz reaction)(h) Phenol to cresol.(i) Phenol to salicylic acid – Kolbe’s method(j) Calcium formate to formaldehyde(k) Calcium formate to acetaldehyde(l) Calcium acetate to acetone(m) Calcium acetate to acetophenone(n) Phenol to picric acid. (o) Proponone to propane (Ketone to alkane - clemmenson’s reduction)(p) Amides to primary amines (Hoffmann’s bromamide reaction)(q) Alkenes to monohaloalkanes (Markownikoff’s effect, peroxide effect)(r) Benzaldehyde to cinnamic acid(perkin’s reaction)(s) How is crotonaldehyde formed?(t) Nitroethane to ethanamine.(u) Nitrobenzene to aniline(benzenamine)(v) Ethanenitrile to ethanamine(w) Benzonitrile to benzyl amine(x) Methanamine to methyl alcohol ( 10 amines to alcohol reaction with nitrous acid)(y) Aniline to Benzene diazonium chloride(z) Methylamine to methyl isocyanide

17. Named reactions:(a) Wurtz fitting reaction(b) Wurtz reation(c) Darzen’s process(d) Dehydrohalongenation (Saytzeff’s rule)(e) Kolbe’s reaction(f) Perkin’s condensation.(g) Esterification reaction.(h) Cannizaro’s reaction(i) Carbylamine reaction(j) Hoffmann’s bromamide reaction(k) Diazotisation reaction(l) Decarboxylation reaction(m) Friedel craft reaction (alkylation and acylation)(n) Saponification reaction

PART D2

1. Preparation of m-dinitrobenzene from nitrobenzene. (3)2. Preparation of p-Bromoacetanilide from Acetanilide. (3)3. Study the effect of concentration on the rate of reaction of potassium persulphate with potassium iodide. (5)4. Study the effect of temperature on the rate of reaction of potassium persulphate with potassium iodide. (5)

5. Determination of velocity constant of acid hydrolysis of methyl acetate. (5)6. Titration FAS vs potassium dichromate. (5)7. Titration Potassium permanganate vs oxalic acid. (5)8. Titration potassium permanganate vs FAS. (5)9. Test for Carbohydrates (2 Mark each)

(a) Molisch’s test (b)Benedict’s test (c)Tollen’s reagent (d)Seliwanoff’s test (e)Iodine test10. Test for Oils and fats (2 mark each)

(a) Saponification (b)Acrolein test11. Test for protein

(a) Biuret test (b)Ninhydrin test (c)Xanthoprotic test (d)Millon’s test

Organic chemistry

1 Mark questions

1. Between methanamine and benzenamine which has got lower pka value?2. Name the organic product obtained when the vapours of secondary alcohol is passed over copper

gauze catalyst.3. Give the IUPAC name of the organic compound obtained when nitrobenzene is heated with tin and

concentrated HCl.4. Write the structural formula of pyrogallol.5. What is Tollen’s reagent?6. Give an example for a reducing / non-reducing sugar.7. Which is the most stable conformation for cyclohexane.8. An haloalkane is prepared using an alcohol and PX3. Give the equation for the reaction.9. What is the condition for an alkene to exhibit geometric isomerism?10. Give the formula for lysine.11. Identify a , b , c, d in the following reaction:

C2H5OH acid KMnO4 A B C CH3NH2 CH3OH12. Name the reagent used to convert methyl amine to methyl isocyanide.13. Name the product formed when phenol is heated with NaOH and Chloroform.14. Define Specific rotation.15. Name the cycloalkane which is the least stable.16. Name the cycloalkane which is the most reactive.17. How many aminoacids residue are present in a tripeptide.18. Give the formula of a chemical compound formed when methyl amine is heated with chloroform and

alcoholic potash.19. Name the reagent used in clemmenson’s reduction.20. What is a chiral carbon atom?21. Give the general formula of cycloalkanes.22. Give the IUPAC name of acetic acid.23. Which is the organic product obtained when methyl magnesium iodide reacts with formaldehyde

followed by acid hydrolysis.24. How many aminoacid units are present in insulin?25. Give the formula for alanine.26. Name the final product when primary amine is subjected to alkylation.27. Write the general formula for wurtz reation.28. What is meant by denaturation of protein?29. What is rancidity of oils? How can it be prevented30. Name the reagent employed to convert bromoethane to ethane.31. What is the chemical name of cumene?32. Give an example of drying of oils.33. Name the substance that decolourise an oil.

34. What type of linkage is present between the polypeptide chains of insulin?35. Name the gas liberated when bromoethane is heated with alcoholic potash.36. Phenol does not react with sodium bicarbonate. Why?37. Name the protein present in hair.38. Name the electronic effect which involves partial displacement of electrons.39. What is a peptide bond?40. What are triglycerides?41. Give a chemical reaction to show that a molecule glucose contains five hydroxyl groups.42. How many π electron are present in the delocalised electron cloud in a benzene molecule.43. Name an amino acid containing aromatic ring.44. Define the term ‘ isoelectric point’.45. Give two uses of methanol.46. What type of mesomeric effect is exhibited by –NO2 group.47. Name the chemical reagent used to remove colloidal impurities from oil.48. Write the IUPAC name of picric acid.49. Give a chemical reaction to show that a molecule of glucose contains a carbonyl group.50. One mole of a given amine consumes two moles of methyl iodide for exhaustive methylation. What

type of amine is this?51. What is iodine value?52. Describe the function of transport agent.53. What are biochemical messengers?54. At what temperature enzyme activity is maximum.55. What happens when butter is exposed to air?56. Name the enzyme which hydrolyses oils and fats into glycerol and fatty acids.57. Give an example for a reducing dissacharide.58. Name the gas liberated when methyl amine reacts with nitrous acid.59. Arrange acetic acid, monochloroacetic acid, trichloroacetic acid and dichloroacetic acid in the

increasing order of acidic strength.60. What is Fehling’s solution?61. Give reason why benzaldehyde gives Cannizaro reaction.62. What is the effect of the following groups on the acidity of phenol – (a) –CH3

(b) –NO2

63. Which fraction of coal tar contains phenol ?64. What are Grignard reagents?65. Name the reagent that brings about dehydrohalogenation.66. What are enantiomers?67. What is a racemic mixture?68. What are meso compounds? Give one example.69. How many optical isomers are possible for a molecule, which contains 4 asymmetric carbon atoms?70. What are laevorotatory compounds?71. What are dextrorotatory compounds?72.