pradeep sharma, - pics institute - art of teaching sharma, institute of competitive studies, sector...

PRADEEP SHARMA, INSTITUTE OF COMPETITIVE STUDIES, SECTOR – 15 , SONEPAT CONTACT NUMBER : 0130 – 2231322 , E – mail : [email protected]

1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. Give SI definition of one mole ? 2. Give the atomic number of element whose outer electronic configuration is: a. 3s1 b. 3d6 3. What conclusion you draw from the study of line spectrum & adsorption spectrum? 4. Give the Bohr’s postulate of angular momentum 5. Why electronic energy is negative? 6. What will be the mass of one 12C atom in g ? 7. How many nodes are present in following – (a) 4 dxy (b) 5 pz (c) 5dz2 (d) 1s

8. How many significant figures are present in the following? (i) 0.0025 (ii) 208 9. Calculate energy of one mole of photons of radiation whose frequency is 5 x1014 Hz. 10. Calculate the molarity of NaOH in the solution prepared by dissolving its 4 g in enough water to form 250 mL of the solution. 11. An element with mass number 81 contains 31.7% more neutrons as compared to protons. Assign the atomic symbol. 12. Derive relation between molecular formula & vapour density. 13. 1.615 gm anhydrous ZnSO4 was placed in moist air . After a few days wt. was found to be 2.875 g . What is the molecular formula of the hydrated salt. 14. Which one of the following will have largest number of atoms? (i) 1 g Au (s) (ii) 1 g Na (s) (iii) 1 g Li (s) (iv) 1 g of Cl2 (g) 15. Electromagnetic radiations of 242 nm is just sufficient to ionize sodium atom . Calculate the ionization energy in J mol-1 . [ h = 6.62 x 10-34 Js , c = 3 x 108 ms-1 , NA = 6.023 x 1023 mol-1 ] 16. Arrange the following in increasing order of their ionic radii – Li+,Mg2+,K+,Al3+. 17. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate threshold frequency (n0) and work function (W0 ) of the metal. 18. The following data are obtained when dinitrogen and dioxygen react together to form different compounds : Mass of dinitrogen Mass of dioxygen (i) 14 g 16 g (ii) 14 g 32 g (iii) 28 g 32 g (iv) 28 g 80 g Which law of chemical combination is obeyed by the above experimental data? Give its statement. 19. (i) An atomic orbital has n = 3. What are the possible values of l and ml ? (ii) List the quantum numbers (ml and l ) of electrons for 3d orbital. (iii) Which of the following orbitals are possible? 1p, 2s, 2p and 3f 20. How much energy is required to ionize a hydrogen atom if an electron occupies n = 2 orbit ? Compare the answer with the ionisation energy of H-atom ( energy required to remove the e- from n = 1 orbit ) 21. Use the data given in the following table to calculate the molar mass of naturally occuring argon isotopes: Isotope Isotopic molar mass Abundance 36Ar 35.96755 g mol–1 0.337% 38Ar 37.96272 g mol–1 0.063% 40Ar 39.9624 g mol–1 99.600%

22. Give the wavelength of first line , limiting and third line in Balmer series of He+ ion. 23. Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation: N2(g) + H2 (g) 2NH3 (g) (i) Calculate the mass of ammonia produced if 2.00 x 103 g dinitrogen reacts with 1.00 x103 g of dihydrogen. (ii) Will any of the two reactants remain unreacted? (iii) If yes, which one and what would be its mass? 24. A Proton is associated with a velocity of 3 x 10-7 ms-1. If the velocity can be measured with a precision or accquracy of + 0.5% . Calculate the uncertainty in position of Proton – mass of Proton =1.66 x 10-27 Kg. 25. (i) The energy associated with the first orbit in the hydrogen atom is –2.18 × 10–18 J atom–1. What is the energy associated with the fifth orbit? (ii) Calculate the radius of Bohr’s fifth orbit for hydrogen atom. 26. A sample of drinking water was found to be severely contaminated with chloroform, CHCl3, supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass). (i) Express this in percent by mass. (ii) Determine the molality of chloroform in the water sample. 27. Define (i) Aufbau principle (ii) Hund’s rule (iii) Heisenberg uncertainity principle 28.(a) A photon of wavelength 4 x 10–7 m strikes on metal surface, the work function of the metal being 2.13 eV. Calculate (i) the energy of the photon(eV), (ii) the kinetic energy of the emission, and (iii) the velocity of the photoelectron (1 eV= 1.6020 × 10–19 J). (b). What is the maximum number of emission lines when the excited electron of a H atom in n = 6 drops to the ground state? 29. (a) 500 mL of 0.250 M NaSO4 solution is added to an aqueous solution of 15.00 g of BaCl2 resulting in the formation of white precipitate of BaSO4. How many moles and how many grams of BaSO4 are formed ? (b) The translation energy possessed by an atom is given by the formula 3/2 kT . Find the de – Broglie wave length of the hydrogen atom with

this translational energy at 25oC. 30. A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives 3.38 g carbon dioxide , 0.690 g of water and no other products. A volume of 10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Calculate (i) empirical formula, (ii) molar mass of the gas, and (iii) molecular formula.


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. Define 1 a.m.u. 2. What is the total number of orbitals associated with the principal quantum number n = 3 ? 3. Calculate the molarity of pure water ? ( d = 1 g / cc ) 4. What is the difference b/n Atomic mass & gm. atomic mass 5. Give the difference b/n orbit and orbital. 6. Why line spectrum is also known as Finger prints? 7. State Dalton’s law of partial pressure . 8. Write down the quantum number for highest energy sub shell in case of Fe+2 . ( At. No. of Fe is 26 ) 9. Why e- can not exist in nucleus ? 10. Chlorophyll contain 2.68% of Mg by mass .Calculate number of Mg atom in 2..00gm of chlorophyll? 11. Find out the wavelength of light emitted when electron jumps from 2nd excited state to ground state in He+ . 12. If the density of methanol is 0.793 kg L–1, what is its volume needed for making 2.5 L of its 0.25 M solution? 13.Energy of an electron in ground state of hydrogen atom is –2.18 x10–18J.Calculate the ionization enthalpy of atomic hydrogen in terms of J mol–1. 14. Wave length of 1st line in Balmer series is 656 nm .Calculate wave length of 2nd line and limiting line in Balmer series. 15. calculate number of atom in following- a. 52 moles of Ar b. 52 a.m.u. of He c. 52 gm He 16. The vividh Bharti station of all India radio delhi broadcast at a frequency of 1368 kHz . Calculate wave length ofelectromagnetic radiation emitted by the transmitter . Which part of electromagnetic spectrum does it belong ? 17. 2.16 gm of Cu when treated with nitric acid gave 2.70 gm of copper oxide .In another expt. 1.15 gm of copper oxide upon reduction with hydrogen gave 0.92 gm Cu. Show that above data illustrate law of definite proportion. 18. The e- energy of ground state of H-atom works out to be – 1.312 x 106 J mol-1.What change occur in the position of e- in this atom if energy of 9.84 x 105 Jmol-1 is added to H-atom. 19. (a) Give significance of . (b) Which shell first of all will have g- subshell. (c) Define PAULIE”s exclusion principle. 20. Find the total number & total mass of protons present in 34 mg of NH3 at S.T.P ? 21. Chlorine is prepared in the laboratory by treating manganese dioxide (MnO2) with aqueous hydrochloric acid according to the reaction 4 HCl (aq) + MnO2(s) 2H2O (l) + MnCl2(aq) + Cl2 (g) How many grams of HCl react with 5.0 g of manganese dioxide? 22. For an atom 2K , 8L , 14M , 2N , Find – (a) Quantum no. for Highest energy e- . (b) Total electron with clock wise & anti clock wise spin . (c) Total magnetic moment 23. 1.0 magnesium is burnt in a closed container which contains 0.6 g of Oxygen. (a) Which reactant is left in excess (b) Find the mass of excess reactant. (c) How many milimetres of o.5 N H2SO4 will dissolve the residue in the vessel. 24 . 0.5 mole each of H2S & SO2 mixed together in a reaction flask according to the equation – 2H2S + SO2 2H2O + 3S . Calculate the

number of mole of S formed.

25. Find out average atomic mass of oxygen from following- element abundance (a) O15

0.9051 (b) O16 0.0027 (c) O17 0.0922

26. A metal form two oxide, lower oxide & higher oxide. The higher oxide contain 80% metal. 0.72 gm of lower oxide gave 0.8 gm of higher oxide when oxidized, Show the data illustrate law multiple proportion. 27. Calculte the mass of 60% H2SO4 required to decompose 50 g of chalk 28. a. Why de-Broglie principle has no significance in case of macroscopic particle? b. A moving e- has K.E. 4.9 x 10-25 J . Find out its de- Broglie wave length? c. . Explain the occurrence of large number of lines in H- spectrum . Also give BALMER formula. 29. (a) Butyric acid contains only C,H & O . A 4.24 mg sample of butyric acid is burnt. It give 8.45 mg of CO2 & 3.46mg of H2O. molecular mass 88. Find out molecular formula. (b) Calculate the mass of CO2 which contain same number of molecule as are contained in 40 gm of O2. 30. (a) A bottle of H2SO4 of density 1.787 gm / c.c. is labelled 86 % by wt. What is the molarity of the solution and what volume of acid is required to make it 1 lt of .2 molar H2SO4 ? (b) What are the dimensions of Planck’s constant & Which other thermodynamic quantity possess same units ? (c) Calculate the uncertainty in position of a dust particles with mass equal to 1 mg, if uncertainty in its velocity is 5.5 x 10-20 ms-1.


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. Which out of diamond & Graphite possess standard enthalpy of formation is equal to zero & why ? 2. Compare Bond angle of H2O and H2S. 3. What would be the IUPAC name and symbol for the element with atomic number 120? 4. Why it is not possible to calculate absolute value of internal energy? 5. Arrange the hydride of gp. 17 in order of boiling point. 6. Find out M.pt. of KCl if ΔHf

° = 7.23KJ/mol & ΔS = 7.0KJ/mol.

7. Which of the following will have the most negative electron gain enthalpy and which the least negative? P, S, Cl, F. 8. State Hess’s law ? 9. NaCl solution gives a white ppt. with AgNO3 solution but CCl4 or chloroform does not. Why? 10. Derive relation b/n Cv & Cp . 11. Compare I .E1 ,I .E2 & I . E3 of 13Al & 12Mg. 12. Is there any change in the hybridization of B and N atoms as a result of the reaction , BF3 + NH3 F3B NH3? 13. Define Periodicity & cause of periodicity . 14. Give the significance of ∆ H and ∆E. 15. Consider the following species : N3–, O2–, F–, Na+, Mg2+ and Al3+ (a) What is common in them? (b) Arrange them in the order of increasing ionic radii. 16. Arrange the following in increasing order of their ionic radii – Li+,Mg2+,K+,Al3+. 17. Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2 is linear. Explain this on the basis of dipole moment. 18. Define hydrogen bond. Is it weaker or stronger than the van der Waals forces?

19. Calculate the enthalpy of hydrogenation of C2H2(g) to C2H4(g) Given bond energies: C – H: 414.0 KJmol-1,C≡C : 827,6 KJ mol-1,C = C : 606.0 KJ mol-1, H – H = 430.5KJ mol-1

20. Calculate the enthalpy change for following reaction --- 2H2O2 2H2O + O2, Given that the standard ΔH°f of H2O2 = -188KJ and ΔH°f H2O = -286.0KJ/mol.State whether Reaction is exothermic or endothermic ? 21. Calculate the enthalpy change for process – CCl4 (g) - C(g) + 4 Cl (g) and calculate bond enthalpy of C—Cl in CCl4 (g) . Given : Δ vap H0 ( CCl4 ) = 30.5 kJ /mol ,Δ f H0 ( CCl4 ) = - 135.5 kJ/mol ; Δ a H0 ( C) = 715.0 kJ/mol . where Δa H0 is enthalpy of atomisation. Δ a H0 ( Cl2 ) = 242 kJ/mol 22. Classify following into ( A) isotope (B) Isotone (C) isobar (D) isoster (E) isodiapher -

a. 2311Na b. 40

20Ca c. 23592U d. 231

90Th e. 3919K f. 24

11Na g. 199F h. 207

82Pb i. 4018Ar j. 18

8O 23. . Define enthalpy of neutralization & why it is 55.1 kJ in case of neutralization of NH4OH & HCl.Find out the enthalpy of ionisation of NH4OH. 24. Calculate the enthalpy of formation of acetic acid if the enthalpy of combustion to CO2 (g) and H2O (l) is -867 kJ mol-1 and enthalpies of formation of CO2(g) and H2O (l) are -393.5 and -285.9 kJ mol-1 25. Describe the hybridisation in case of PCl5. Why are the axial bonds longer as compared to equatorial bonds ? 26. The reaction of cyanamide,NH2CN with dihydrogen was carried out in a bomb calorimeter,& U was Found to be – 742.7 kJ/mol at 298 K. Calculate the enthalpy change of the reaction at 298 K.

NH2CN (s) + 3/2 O2 (g) N2 (g) + CO2 (g) + H2O (l) 27. The heat of combustion of benzene in a bomb calorimeter ( i.e constant volume ) was found to be 32.63.9 kJ/mol at 250 C. Calculate the heat of

combustion of benzene at constant pressure. 28 (i) Define (a) Enthalpy of solution (b) State variable (c) Standard free energy change . (ii) Write the gp. , period , block No. of following – (1) 37X (2) 42Y (iii) ∆Gf

0 for elementary substance is zero but ∆Sf

0 is not .Why? 29. The first ( ∆i H1) and the second (∆i H2) ionization enthalpies (in kJ mol–1) and the (∆egH) electron gain enthalpy (in kJ mol–1) of a few elements are given below: Elements ∆i H1 ∆i H2 ∆eg H I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (a) the least reactive element. (b) the most reactive metal. (c) the most reactive non-metal. (d) the least reactive non-metal. (e) the metal which can form a stable binary halide of the formula MX2(X=halogen). (f) the metal which can form a predominantly stable covalent halide of the formula MX (X=halogen)? 30. (a) Explain the formation of H2 molecule on the basis of valence bond theory. (b) Distinguish between a sigma and a pi bond. (c) What is meant by the term bond order ? Calculate the bond order of : N2, O2, O2

+ and O2–.


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. All the bond dissociation energies in CH4 are not same . Comment . 2. Why PH3 has zero dipole moment ? 3. Draw the Lewis structures for the following molecules and ions:CO3

-2 , HCOOH 4. Why Fe attracts O2 molecule only and O2

-2 is not attracted by magnet. 5. Why compounds of carbon can’t have square planer geometry?

6. Trans –2,3- dihydroxy but –2-ene-1,4-di oic acid have high boiling point than cis-2,3-dihydroxy but –2-ene –1,4- dioic acid, why? 7. Write general outer e- configuration of d block elements. 8. Which of the following are isoelectronic species i.e., those having the same number of electrons? Na+, K+, Mg2+, Ca2+ , S2–, Ar. 9. Arrange the following molecules in order of increasing ionic character of their bonds: LiF, K2O, N2 , SO2 , ClF3. 10. Compare the dipole moment of NH3 & NF3 . 11. Comment on the statement that ionic bond is the extreme case of polar covalent bond?

12. The boiling and melting points of water are abnormally higher than those of other hybrids of group 16 of the periodic table . Give reasons 13.. Derive ∆ G = - RTln Kp

14.. Explain why BeH2 molecule has a zero dipole moment although the Be–H bonds are polar. 15. Calculate the entropy change in surroundings when 1.00 mol of H2O(l) is formed under standard conditions. .∆f H0 = –286 kJ mol–1. 16. Which of the following process is possible- (a)C2 + e- C2

- (b) C2 C2+ + e-.

17. Use LCAO method for the formation of molecular orbitals in case of homonuclear diatomic hydrogen molecule. 18. What is the total number of sigma and pi bonds in the following molecules ? (a) C2H2 (b) C2H4 19. Discuss the relative stability and magnetism of N2, N2

+,N2-. _ _

20. (a) Describe the change in hybridisation (if any) of the Al atom in the following reaction. AlCl3 + Cl AlCl4 (b) In a process,701 J of heat is absorbed by a system & 394 J of work is done by system.What is the change in internal energy of the process ?

21. What is meant by hybridisation of atomic orbitals? Discuss the hybridization of acetylene, C2H2. 22. A swimmer coming out from a pool is covered with a film of water weighing about 18g. How much heat must be supplied to evaporate this water at 298 K ? Calculate the internal energy of vaporisation at 100°C. ∆vapH for water at 373K = 40.66 kJ mol–1 23. Assign the position of the element having outer electronic configuration : (a) n s2 np4 for n = 3 (b) ( n – 1 ) d2 ns2 n=4 (c) ( n – 2 ) f7 ( n – 1 ) d1 n s2 for n = 6 in the periodic table. 24. Explain the following - ( a ) Fe+3 is more stable than Fe+2 ( b ) It is difficult to prepare N-3 ion ( c ) Cs is better photo emissive than Na 25. The combustion of one mole of benzene takes place at 298 K & 1 atm.After combustion, CO2(g) and H2O (1) are produced and 3267.0 kJ of heat is liberated. Calculate the standard enthalpy of formation, ∆f H0 of benzene. Standard enthalpies of formation of CO2(g) and H2O(l) are - 393.5 kJ mol–1 and – 285.83 kJ mol–1 respectively. 26. Among the second period elements the actual ionization enthalpies are in the order Li < B < Be < C < O < N < F < Ne. Explain why (i) Be has higher ∆I H than B (ii) O has lower ∆i H than N and F? 27. Compare the relative stability of the following species and indicate their magnetic properties; O2 , O2

- ,O22- ,O2

+

28. (i) Dipole moment of HCl is 1.03 D & its Bond length is 1.257A0.For 100% ionic character , the charge developed on H & Cl atom would be 4.8x10-10e.s.u cm. Find %age ionic character. (ii) What type(s) of intermolecular forces exist b/w the following pairs?

(a) HBr and H2S , (b) Cl2 and CBr4 , (c) I2 and NO3

- , (d) NH3 and C6H6 ?

(iii) Write down the difference between Bonding M. O. and Antibonding M.O. 29. (a) . In SF4 molecule, lone pair of e- occupy an equatorial position rather than axial position in the over all trigonal bipyramidal arrangement.why? (b) Arrange the following in the order of bond length – (i) H-I , H-Br , H-F , H-Cl (ii) CH ≡CH , CH3-CH3 , CH2= CH2 (iii) F2 , Cl2 , I2 , Br2 (iv) C-C , N-N , O-O , F-F (c) Find out formal charge on following:- (i) CO3

-2 (ii ) [ O=N-O ] (iii) NH4+ (4) O3

30. a. How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium? b. Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) O or F (ii) F or Cl c. What is the basic difference between the terms electron gain enthalpy and electronegativity?


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. What is the effect of conc. on electrode potential ? 2. Which is heavier dry air or moist air & why? 3. What is the difference b/n evaporation and boiling? 4. Indicate the inductive effect in chloropropane. 5. Which of the following does not show disproportionation reaction – ClO- , ClO2

- , ClO3- & ClO4

- 6. What is Boltz mann’s constant and its value? 7. A gas ‘A’, M.M. 4 diffuse thrice as fast as the gas B. What will be the M.M. of B? 8. Under what conditions of T & P , most of the gas deviate from ideal behaviour 9. 2.9 g of a gas at 95 °C occupied the same volume as 0.184 g of dihydrogen at 17 °C, at the same pressure. What is the molar mass of the gas? 10. Comment on the statement that oxidation & reduction are complementary to each other ? 11. Derive Ideal gas equation. 12. Why protonation on phenol is not possible but on alcohol ,it is possible ? 13. . Is it possible to store – (i) Copper sulphate soln in a zinc vessel (ii) CuSO4 soln in silver vessel 14. While sulphur dioxide and hydrogen peroxide can act as oxidising as well as reducing agents in their reactions, ozone and nitric acid act only as oxidants. Why ? 15. What will be the pressure of the gas mixture when 0.5 lt. of H2 at 0.8 bar and 2.0 l of oxygen at 0.7 bar are introduced in 1 vessel at 27oC. 16. Critical temperature for carbon dioxide and methane are 31.1 °C and –81.9 °C respectively. Which of these has stronger intermolecular forces and why? 17. Why does the following reaction occur ? XeO6

4– (aq) + 2F – (aq) + 6H+(aq) XeO3 (g)+ F2 (g) + 3H2O(l) What conclusion about the compound Na4XeO6 (of which XeO6

4- is a part) can be drawn from the reaction. 18. Arrange the following in order of their acidic strength – a. NH2-COOH ,HCOOH,CH3COOH b.CH3CH(CN)CH2COOH, CH3CH2CH(CN)COOH 19. A manometer is connected to a gas containing bulb. The open arm reads 43.7cm, whereas arm connected to bulb reads 15.6 cm. If the barometer pressure is 743 mmHg , What is the pressure of gas in bar? 20.(a) Select the group +I and –I effect from the following list – a. –NO2 b. –COO- c. CN- d. CI e. OH f. CH3

- g. C2H5- h. COOH

(b) On a ship sailing in pacific ocean where temperature is 23.4 °C , a balloon is filled with 2 L air. What will be the volume of the balloon when the ship reaches Indian ocean, where temperature is 26.1°C ? 21. Balance the following redox reaction – a ) I- + IO3

- + H+ I2 + H2O b) Cr2O7

-2 + C2H4O Cr+3 + C2H4O2 c ) Cl2O7 + H2O2 ClO2

- + O2 22. Density of a gas is found to be 5.46 g/dm3 at 27 °C at 2 bar pressure. What will be its density at STP? 23. . A spherical balloon of 21 cm diameter is to be filled with H2 at NTP from a cylinde containing the gas at 20 atm. & 270C..The cylinder can hold 2.82 lt. of liquid. Calculate number of balloons that can be filled up. 24. Which of following pair do not constitute toward resonance structure – a. CH3NO2 & CH3ONO b. (CH3)2CO & CH3-C(OH)=CH2 c. CH3CH=CHCH3 & CH3CH2CH=CH2 25. . A Ne – O2 mixture contains 70.6 g of O2 & 167.5 g of Ne. If the pressure of the mixture of the gases in the cylinder is 25 bar , what is the partial pressure of O2 & Ne in the mixture . (Ne=20 u ) 26. Give reasons :- (a) Tyre of automobile are inflated to lower pressure in summers. (b) Liquid ammonia bottle is cooled before opening . (c) The aquatic animals are less in the lakes of mountains . 27. Write the difference b/n – a.Singlet carbene and Triplet Carbene b. Electrophile and nucleophilic

28. (a) The emf of the cellCu /CuSO4(aq)(a = 0.2) ||CuSO4(X) |Cu is -0.03 Volt at 25oC. What will be the value of activity (X) of CuSO4 solution on , the right hand side electrode ?

(b) The standard oxidation potentials E- for the half reactions are given Al Al3 + 3e- Eo = 1.66V Fe Fe2+ + 2e- Eo = 0.41 V What will be the EMF of the cell reaction Fe++ + Al Al+++ + Fe ? (c) (x) MnO4

- + (y) H2O2 2Mn+2 + 5H2O + 9O2 + (z)e- ,In this reaction , Find the value of (x) ,(y) and (z) ?

29. (a) At 0oC , the density of a certain oxide of a gas at 2 bar is same as that of nitrogen at 5 bar . What is the molecular mass of oxide

(b) State the law of multiple proportion with example.

(c) Derive K.E = 1/3 mnu2

30.(a) Which out of acetic acid,bromo acetic acid ,& chloroacetic acid is stronger & why. (b)Which out of ethanamine,N-Methyl methanamine & N,N-Dimethyl methanamine is more basic & why ? (c) Arrange the following in order of basic strength – a. CH3-CH2-NH2 , NH3,CH3-NH-CH3

b. NH3 , NO2-NH2 , CH3-NH2, CH3-NH+ - CH3


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. Why mountaineers carry oxygen cylinder along with them? 2. . Find out O.N. of each chlorine atom in bleaching powder , CaOCl2 3. Find out the volume of 1 mole of gas at STP. 4. Why the size of weather balloon increases when it goes up in the sky? 5. State Avogadro’s law? 6. At 25°C and 760 mm of Hg pressure a gas occupies 600 mL volume. What will be its pressure at a height where temperature is 10°C and volume of the gas is 640 mL. 7. what is Boyle’s temperature? 8. Define compressibility Factor ? 9. Consider the elements : Cs, Ne, I and F (a) Identify the element that exhibits only postive oxidation state. (b) Identify the element that exhibits both positive and negative oxidation states. (c) Identify the element which exhibits neither the negative nor does the positive oxidation state. 10. What happen if we remove salt bridge? 11. 500 ml of nitrogen at 27oC are cooled to -5 oC at the same pressure .Calculate the new volume. 12. Derive the relation b/n Cp and Cv. 13. Why H2S act as reductant but SO2 act as reductant as well s oxidant both? 14. What type(s) of intermolecular forces exist b/w the following pairs?

(a) HBr and H2S , (b) Cl2 and CBr4 , (c) I2 and NO3

- , (d) NH3 and C6H6 ?

15. A sealed tube which can withstand a pressure of 3 atm is filled with air at 27o C & 760 mm pressure . Find the temp. Find the temp. above which it will burst. 16. Using the equation of state pV = nRT , show that at a given temperature , density of a gas is directly proportional to gas pressure ‘ p ‘ 17. Chloride ions reduces MnO2 to Mn(II) & it self oxidized to form chlorine gas in acidic medium.Give the balance redox reaction. 18. What is the ratio of average K.E. of oxygen molecules to that of ozone molecule at 27oC? 19. A student set up the apparatus at room temperature (27oC) . By mistake without adding the reaction mixture he started heating the flask .By the time he realized his mistake, the temperature had shot up to 477oC as recorded by pyrometer , What fraction of air would have been expelled out? 20. How much time would it take to distribute one Avogadro number of wheat grains, if 1010 grains are distributed each second ? 21. What is absolute zero temp. ? How charle’s law leads to the absolute zero temp. ? 22. Arrange the following compound in order of decreasing relative reactive with an electrophile – a. chlorobenzene b. p – nitrochlorobenzene . 23. Calculate the oxidation number of sulphur, chromium and nitrogen in H2SO5, Cr2O7

2– and NO3–. Suggest structure of these compounds.

24. Arrange the following Carbonium ions in the order of stability with reason – a. CH2=CH-CH2

+ b.CH2=CH+ c. CH3 – CH2+

25. a) Draw the resonating structure of Aniline , nitrobenzene & But-2-enol. (b) Which out of vinyl chloride & allyl chloride is more reactive & why ? 26. The average K.E. of a gas molecule 0oC is 5.621 X 10-21J. Calculate Boltzman constant .Also calculate the number of molecule present in one . mole of the gas. 27. Pay load is defined as the difference b/n the mass of displaced air & mass of balloon.Calculate the pay load when a balloon of radius 10 m,mass 100 kg is filled with helium at 1.66 bar at 270C. ( Density of air 1.2 kg/m3 ) 28. Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent. (a) P4(s) + OH–(aq) PH3(g) + HPO2

– (aq) (b) N2H4(l) + ClO3

–(aq) NO(g) + Cl–(g) (c) Cl2O7(g) + H2O(aq) ClO2

- (aq) + O2 (g) + H+ (d) P + OH- PH3 + H2PO3 (e) Fe(OH)2 + H2O2 2Fe(OH)3 29. (a) Explain the significance of Vander Waal’s parameter ? (b) A large flask fitted with a stop cock is evacuated & weighed ; its mass is found to be 134.567 g . It is then filled to a pressure of 735 mm at 31oC with a gas of unknown molecular mass & then reweighed ; its mass is 137.456 g . The flask is then filled with water & weighed again ; its mass is now 1067.9 g . Assuming that the gas is ideal , calculate the molar mass 30.(a)In Ostwald’s process for the manufacture of nitric acid, the first step involves the oxidation of ammonia gas by oxygen gas to give nitric oxide gas and steam.What is the maximum weight of nitric oxide that can be obtained starting only with 10.00 g. of ammonia and 20.00 g of oxygen? (b) Using the standard electrode potentials , predict if the reaction between the following is feasible: (a) Fe3+(aq) and I–(aq) (b) Ag+(aq) and Cu(s) (c) Fe3+ (aq) and Cu(s) (d) Ag(s) and Fe3+(aq) (e) Br2(aq) and Fe2+(aq).


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. What are olefins & why they are named so ? 2. Arrange benzene, n-hexane and ethyne in decreasing order of acidic behaviour. Also give reason for this behaviour. 3. Suggest the name of a Lewis acid other than anhydrous aluminium chloride which can be used during ethylation of benzene. 4. What is markovnikov’s addition? 5. Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene? 6. Write structures of all the alkenes which on hydrogenation give 2-methylbutane. 7. Why is benzene extra – ordinary stable ? 8. Identify 1o, 2o and 3o C in the following and also count the 1o, 2o and 3o Hydrogen in – CH3CH2-C(CH3)2-CH2-CH(CH3)2 . 9. Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example. 10. Out of Benzene , m – dinitrobenzene and Toluene which will undergo nitration most easily and why? 11. Arrange following in the order of boiling point , with reason. n-pentane , isopentane , neo-pentane . 12. An alkene ‘A’ contains three C – C, eight C – H s bonds and one C – C p bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’. 13. How do you account for the formation of ethane during chlorination of methane ? 14. Draw cis and trans isomers of the following compounds. Also write their IUPAC names : (a) CHCl = CHCl (b) C2H5CCH3 = CCH3C2H5 15. Write IUPAC names of the products obtained by addition reactions of HBr to hex-1-ene (i) in the absence of peroxide and (ii) in the presence of peroxide. 16. How will you convert Ethanoic acid into Benzene ? 17. Addition of HBr to propene yields 2-bromopropane, while in the presence of benzoyl peroxide, the same reaction yields 1-bromopropane. Explain and give mechanism. 18. What is (a) Octane no. (b) Homologus series. 19. Write a short note on - (a) Friedalcraft acylation ( with mechanism ) (b) Dehydration ( With mechanism ) 20. Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty? 21. Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E+ (a) Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene (b) Toluene, p-H3C– C6H4– NO2 , p-O2N– C6H4 – NO2 . 22. (a)Give the Mechanism of addition of HBr on Buta-1,3-diene. (b)Why conjugated dienes are more reactive yhan alkenes or alkynes towards electrophilic addition reaction.

23. How would you convert the following compounds into benzene? (i) Ethyne (ii) Ethene (iii) Hexane 24. How will you convert benzene into (i) p-nitrobromobenzene (ii) m- nitrochlorobenzene (iii) p - nitrotoluene (iv) acetophenone? 25. Give a distinguishing test for - (a) Butyne & But-2-yne (b) 3-Chloropropene & 2-Chloropropene 26. Convert – a. CH4 to Benzene b. Propene to 3-Chloropropen c. Benzene to Benzene-1,3-dioicacid 27. What happen when sodium salt of unsaturated dicarboxylic acid is electrolysed with water ? Give mechanism. 28. . (i) Write IUPAC name of following compounds :- a. COOH b. C6H5 - N N – C6H5 (ii) Find out R& S configuration of following - NO2 H2N – OCH3 OH (iii) Find D & L configuration - CHO CH2 H – C – OH H – C – OH H (iv) Predict the structure from name :- a. Methyl-4-cyano-3-methoxy butan-1-oate b. Prop-1,2,3- tricarbonitrite 29. a) . Complete the following – CH3CH2Cl A CL2 / LIG B KOH alc C O3/CH2CL2/ Zn/H2O D Cl2 excess E aq.AgOH F 2NaOH /CaO G Ci2 /anhyd. AlCl3 H Na in dry ether I

b) Write a short note on alternation effect. Compare the b.pt. & m.pt of o-dichlorobenzene & p-dichlorobenzene 30.Write the IUPAC name of following organic compounds – (a) CH3-C(CH3) (Et) –C (OCl) – C6H5 (b) CH2 = CH – COONH2 (c) HOOC-CH(OMe) –CH2-COOH (d) NH2CONH2 (e) CH3-C≡ C-CH (CH2CHO) – CH(CH2CONH2)-CH2-CH(CH2CHO)-CH(COOH)-COOH


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed.

1. Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes? 2. Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

3. What happens when equilibrium is restored finally and what will be the final vapour pressure? 4. Calculate the strength of 10 volume solution of H2O2. 5. Both the forward and reverse reactions in the equilibrium are elementary bimolecular reactions. What is Kc, for the reverse reaction? 6. [SiF6]2– is known whereas [SiCl6]2– not. Give possible reasons. 7. Explain why pure liquids and solids can be ignored while writing the equilibrium constant expression? 8. Why does boron triflouride behave as a Lewis acid ? 9. . What are electron deficient compounds ? Are BCl3 and SiCl4 electron deficient species ? Explain. 10. Define ionic product of water. Ionic product of water at 310 K is 2.7 × 10–14. What is the pH of neutral water at this temperature? 11. Carbon monoxide gas is more dangerous than carbon dioxide gas. Why? 12. At equilibrium, the concentrations of N2=3.0 × 10–3M, O2 = 4.2 × 10–3M and NO= 2.8 × 10–3M in a sealed vessel at 800K. What will be Kc for the reaction : N2(g) + O2 �(g) 2NO(g) 13. A sample of HI(g) is placed in flask at a pressure of 0.2 atm. At equilibrium the partial pressure of HI(g) is 0.04 atm. What is Kp for the given equilibrium ? 2HI (g) � H2 (g) + I2 (g) 14. Write the conjugate acids & bases for the following : , NH3 , HSO4

- , HCOO–.,H2O. 15. The concentration of hydrogen ion in a sample of soft drink is 3.8 × 10–3M. what is its pH ? 16. Derive KP = KC (RT)∆ng

17. Describe the shapes of BF3 and BH4–. Assign the hybridisation of boron in these species.

18. (a) H2 (g) + MmOo (s) ∆ (b) CO (g) + H2 (g ∆,catalyst

(c) C3H8 (g) + 3 H2O (g) ∆,catalyst (d) Zn (s) + NaOH (aq) ∆

19. The first ionization constant of H2S is 9.1 × 10–8. Calculate the concentration of HS– ion in its 0.1M solution. How will this concentration be affected if the solution is 0.1M in HCl also ? If the second dissociation constant of H2S is 1.2 × 10–13, calculate the concentration of S2– under both conditions. 20. Justify the given statements and give chemical reactions : a. Lead(II) chloride reacts with Cl2 to give PbCl4. b. Lead(IV) chloride is highly unstable towards heat. c. Lead is known not to form an iodide, PbI4. 21.Calculate the pH of 0.08M solution of hypochlorous acid, HOCl. The ionization constant of the acid is 2.5 × 10–5 .Determine the percent dissociation of HOCl.

22. What do you understand by (i) electron-deficient, (ii) electron- precise, and (iii) electron-rich compounds of hydrogen? Provide justification with suitable examples.

23. Calculate the pH of the following solutions: a) 2 g of TlOH dissolved in water to give 2 litre of solution. b) 0.3 g of Ca(OH)2 dissolved in water to give 500 mL of solution. c) 0.3 g of NaOH dissolved in water to give 200 mL of solution. d) 1mL of 13.6 M HCl is diluted with water to give 1 litre of solution. 24. In Dumas’ method for estimation of nitrogen, 0.3g of an organic compound gave 50mL of nitrogen collected at 300K temperature

and 715mm pressure. Calculate the percentage composition of nitrogen in the compound. (Aqueous tension at 300K=15 mm). 25. What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of ICl was 0.78 M ? 2ICl (g) � I2 (g) + Cl2 (g); Kc = 0.14

26. (a) Explain the principle of paper chromatography. (b) Why is nitric acid added to sodium extract before adding silver nitrate for testing halogens?

27. Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as: CHCOOH (l) + CHOH (l) CHCOOCH (l) + HO (l) (i) Write the concentration ratio (reaction quotient), Qc, for this reaction ( water is not in excess and is not a solvent in this reaction) (ii) At 293 K, if one starts with 1.00 mol of acetic acid and 0.18 mol of ethanol, there is 0.171 mol of ethyl acetate in the final equilibrium mixture. Calculate the equilibrium constant. (iii) Starting with 0.5 mol of ethanol and 1.0 mol of acetic acid and maintaining it at 293 K, 0.214 mol of ethyl acetate is found after sometime. Has equilibrium been reached?

28. (a) During estimation of nitrogen present in an organic compound by Kjeldahl’s method, the ammonia evolved from 0.5 g of the compd in Kjeldahl’s estimation of nitrogen, neutralized 10 mL of 1 M H2SO4. Find out the percentage of nitrogen in the compd. (b) What is the difference between distillation, distillation under reduced pressure and steam distillation ?

29. (i) Explain structures of diborane and boric acid. (ii) What happens when (a) Borax is heated strongly, (b) Boric acid is added to water, (c) Aluminium is treated with dilute NaOH, (d) BF3 is reacted with ammonia ?

30. (a) The ionization constant of propanoic acid is 1.32 × 10–5. Calculate the degree of ionization of the acid in its 0.05M solution and also its pH. What will be its degree of ionization if the solution is 0.01M in HCl also? (b) The solubility of Sr(OH)2 at 298 K is 19.23 g/L of solution. Calculate the concentrations of strontium and hydroxyl ions and the pH of the solution. (c) List gases which are responsible for greenhouse effect.


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. Why Na is kept in kerosene? 2. Why Li is strongest reducing agent ? 3. Write chemical reactions to show the amphoteric nature of water. 4. Why is KO2 paramagnetic ? 5. Predict if the solutions of the following salts are neutral, acidic or basic: NaCl, KBr, NaCN, NH4NO3, NaNO2 and KF. 6. Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base: (a) OH– (b) F– (c) H+ (d) BCl3 . 7. What causes the temporary and permanent hardness of water ? 8. Why Na & K show Different Colour ? 9. Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone ? 10. Among NH3, H2O and HF, which would you expect to have highest magnitude of hydrogen bonding and why? 11. Describe the effect of : a) addition of H2 b) addition of CH3OH c) removal of CO d) removal of CH3OH on the equilibrium of the reaction: 2H2(g) + CO (g) CH3OH (g) 12. The solubility product constant of Ag2CrO4 and AgBr are 1.1 × 10–12 and 5.0 × 10–13 respectively. Calculate the ratio of the molarities of their saturated solutions. 13. Beryllium and magnesium do not give colour to flame whereas other alkaline earth metals do so. Why ? 14. Nitric oxide reacts with Br2 and gives nitrosyl bromide as per reaction : 2NO (g) + Br2 (g) 2NOBr (g) When 0.087 mol of NO and 0.0437 mol of Br2 are mixed in a closed container at constant temperature, 0.0518 mol of NOBr is obtained at equilibrium. Calculate equilibrium amount of NO and Br2 . 15. Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper iodate? (For cupric iodate Ksp = 7.4× 10–8 ).

16.Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor. 17. Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (i) COCl2 (g) CO (g) + Cl2 (g) (ii) CH4 (g) + 2S2 (g) CS2 (g) + 2H2S (g) (iii) CO2 (g) + C (s) 2CO (g) (iv) 2H2 (g) + CO (g) CH3OH (g)

18. Explain why BCl3 molecule has zero dipole moment. 19. Dihydrogen gas used in Haber’s process is produced by reacting methane from natural gas with high temperature steam. The first stage of two stage reaction involves the formation of CO and H2. In second stage, CO formed in first stage is reacted with more steam in water gas shift reaction, CO (g) + H2 �O (g) CO2 (g) + H2 (g) If a reaction vessel at 400°C is charged with an equimolar mixture of CO and steam such that pCO = pH2O = 4.0 bar, what will be the partial pressure of H2 at equilibrium? Kp = 10.1 at 400°C 20. Calculate a) .∆G0 and b) the equilibrium constant for the formation of NO2 from NO and O2 at 298K : NO (g) + ½ O2 (g) NO2 (g) where ∆f G0 (NO2) = 52.0 kJ/mol , ∆f G0 (NO) = 87.0 kJ/mol, ∆f G0 (O2) = 0 kJ/mol

21. Explain the following reactions (a) Silicon is heated with methyl chloride at high temperature in the presence of copper; (b) Silicon dioxide is treated with hydrogen fluoride; (c) CO is heated with ZnO; (d) Hydrated alumina is treated with aqueous NaOH solution.

22. At 473 K, equilibrium constant Kc for decomposition of phosphorus pentachloride, PCl5 is 8.3 ×10-3. If decomposition is depicted as, PCl5 (g) PCl3 (g) + Cl2 (g) ; ∆r H0 = 124.0 kJ mol–1 a) write an expression for Kc for the reaction. b) what is the value of Kc for the reverse reaction at the same temperature ? c) what would be the effect on Kc if (i) more PCl5 is added (ii) pressure is increased (iii) the temperature is increased ? 23. A sample of pure PCl5 was introduced into an evacuated vessel at 473 K. After equilibrium was attained, concentration of PCl5 was found to be 0.5 × 10–1 mol L–1. If value of K c is 8.3 × 10–3, what are the concentrations of PCl3 and Cl2 at equilibrium? PCl5 (g) PCl3 (g) + Cl2(g) 24. Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction: CH4 (g) + H2O (g) CO (g) + 3H2 (g) (a) Write as expression for Kp for the above reaction. (b) How will the values of Kp and composition of equilibrium mixture be affected by (i) increasing the pressure (ii) increasing the temperature (iii) using a catalyst ? 25. What happens when (i) sodium metal is dropped in water ? (ii) sodium metal is heated in free supply of air ? (iii) sodium peroxide dissolves in water ? 26. Bromine monochloride, BrCl decomposes into bromine and chlorine and reaches the equilibrium: 2BrCl (g) Br2 (g) + Cl2 (g) for which K c= 32 at 500 K. If initially pure BrCl is present at a concentration of 3.3 × 10–3 mol L–1, what is its molar concentration in the mixture at equilibrium? 27. . Comment on each of the following observations: (a) The mobilities of the alkali metal ions in aqueous solution are Li+ < Na+ < K+ < Rb+ < Cs+ (b) Lithium is the only alkali metal to form a nitride directly. (c) E0 for M2+ (aq) + 2e– M(s) (where M = Ca, Sr or Ba) is nearly constant. 28. (a) The ionization constant of benzoic acid is 6.46 × 10–5 and Ksp for silver benzoate is 2.5 × 10–13. How many times is silver benzoate more soluble in a buffer of pH 3.19 compared to its solubility in pure water? (b) What is Kc for the following equilibrium when the equilibrium concentration of each substance is: [SO2]= 0.60M, [O2] = 0.82M and [SO3] = 1.90M ? 2SO2(g) + O2(g) 2SO3(g) (c) What are the reactions involved for ozone layer depletion in the stratosphere? 29. Give reasons :

(i) Conc. HNO3 can be transported in aluminium container. (ii) A mixture of dilute NaOH and Al pieces is used to open drain. (iii) Graphite is used as lubricant. (iv) Diamond is used as an abrasive. (v) Aluminium alloys are used to make aircraft body. (vi) Aluminium utensils should not be kept in water overnight. (vii) Aluminium wire is used to make transmission cables.

30. (a) When alkali metal dissolves in liquid NH3 ,solution can acquire different colours.Explain reasons for this type of colour change ? (b) What happens when (i) magnesium is burnt in air (ii) quick lime is heated with silica (iii) chlorine reacts with slaked lime (iv) calcium nitrate is heated ? (c) What do you mean by Biochemical Oxygen Demand (BOD)?


1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each. 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each. 6. Use log tables if necessary, use of calculators is not allowed. 1. Among NH3, H2O and HF, which would you expect to have highest magnitude of hydrogen bonding and why? 2. What is catenation? 3. State as to why a solution of Na2CO3 is alkaline ? 4. Will CCl4 give white precipitate of AgCl on heating it with silver nitrate? Give reason for your answer. 5. Find out volume strength of 1.6 N H2O2 solution. 6. Old Painting of Lead (Pb) are washed with H2O2.why ? 7. Which one of the following alkali metals gives hydrated salts ? (a) Li (b) Na (c) K (d) Cs 8. What happens when (i) sodium metal is dropped in water ? (ii) sodium metal is heated in free supply of air ? 9.Consider the reaction of water with F2 and suggest, in terms of oxidation and reduction, which species are oxidised/reduced. 10. What happens when (i) magnesium is burnt in air (ii) quick lime is heated with silica (iii) chlorine reacts with slaked lime (iv) calcium nitrate is heated ? 11. What are the harmful effects of photochemical smog and how can they be controlled? 12. Discuss the chemistry of Lassaigne’s test.

13.Explain, why an organic liquid vaporises at a temperature below its boiling point in its steam distillation ? 14. (a) Classify following oxides as neutral, acidic, basic or amphoteric: CO2, B2O3, SiO2, CO, Al2O3, PbO2, Tl2O3

(b) Write suitable chemical equations to show their nature. 15. State as to why (a) a solution of Na2CO3 is alkaline ? (b) alkali metals are prepared by electrolysis of their fused chlorides ?

(c) sodium is found to be more useful than potassium ? 16. What do you understand by the term ’auto-protolysis’ of water? What is its significance? 17. Explain (a) inert pair effect (b) allotropy 18. Calcu;ate Normality of solution of 1 lt of H2O2,labeled 30 volume ? 19. How would you explain the following observations? (i) BeO is almost insoluble but BeSO4 in soluble in water, (ii) BaO is soluble but BaSO4 is insoluble in water, (iii) LiI is more soluble than KI in ethanol. 20. Discuss the principle and method of softening of hard water by synthetic ion-exchange resins. 21.Do you expect different products in solution when aluminium(III)chloride and potassium chloride treated separately with (i) normal water

(ii) acidified water, and (iii) alkaline water? Write equations wherever necessary 22.In the estimation of sulphur by Carius method, 0.468 g of an organic sulphur compound afforded 0.668 g of barium sulphate. Find out the percentage of sulphur in the given compound.

23. Discuss the principle of estimation of halogens, sulphur and phosphorus present in an organic compound. 24. What do you understand by the terms: (i) hydrogen economy (ii) hydrogenation (iii) ‘syngas’ (iv) water-gas shift reaction (v) fuel-cell ? 25. Complete the following reactions – (i) PbS (s) + H2O2 (aq) (ii) MnO4

- (aq) + H2O2 (aq) (iii) CaO (s) + H2O (g) (iv) AlCl3 (g) + H2O (l) (v) Ca3N2 (s) + H2O (l) 26. . A certain salt X, gives the following results.

(i) Its aqueous solution is alkaline to litmus. (ii) It swells up to a glassy material Y on strong heating. (iii) When conc. H2SO4 is added to a hot solution of X,white crystal of an acid Z separates out. Write equations for all the above reactions and identify X, Y and Z.

27. Comment on each of the following observations: (a) The mobilities of the alkali metal ions in aqueous solution are Li+ < Na+ < K+ < Rb+ < Cs+ (b) Lithium is the only alkali metal to form a nitride directly. (c) E0 for M2+ (aq) + 2e– M(s) (where M = Ca, Sr or Ba) is nearly constant. 28.Write balanced equations for:

(i) BF3 + LiH (ii) B2H6 + H2O (iii) NaH + B2H6 (iv) H3BO3 heat (v) Al + NaOH (vi) B2H6 + NH3

29. (i) When metal X is treated with sodium hydroxide, a white precipitate (A) is obtained, which is soluble in excess of NaOH to give soluble complex (B). Compound (A) is soluble in dilute HCl to form compound (C). The compound (A) when heated strongly gives (D), which is used to extract metal. Identify (X), (A), (B), (C) and (D). Write suitable equations to support their identities. (ii) When alkali metal dissolves in liquid NH3 ,solution can acquire different colours.Explain reasons for this type of colour change ? 30. (a) 0.3780 g of an organic chloro compound gave 0.5740 g of silver chloride in Carius estimation. Calculate the percentage of chlorine present in the compound.

(b) . Differentiate between the principle of estimation of nitrogen in an organic compd by (i) Dumas method and (ii) Kjeldahl’s method. (c) Calculate the volume strength of a 3% solution of H2O2 .

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