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CBSE / NCERT Class 11 Chemistry Practice Question Papers

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Brain Grain · braingrain.in
Chemistry — Practice Paper · Set 1
Class: 11CBSE / NCERTMax Marks: 43
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 15 × 1 = 15

Choose the correct answer. (Answer all questions.)

1.The size of isoelectronic species — F-, Ne and Na+ is affected by (a) nuclear charge (Z ) (b) valence principal quantum number (n) (c) electron-electron interaction in the outer orbitals (d) none of the factors because their size is the same.a. nuclear charge (Z )b. valence principal quantum number (n)c. electron-electron interaction in the outer orbitalsd. none of the factors because their size is the same.[1]
2.Which of the following statements related to the modern periodic table is incorrect? (a) The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell. (b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell. (c) Each block contains a number of columns equal to the number of electrons that can occupy that subshell. (d) The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.a. The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell.b. The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.c. Each block contains a number of columns equal to the number of electrons that can occupy that subshell.d. The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.[1]
3.Which one of the following statements is incorrect in relation to ionization enthalpy? (a) Ionization enthalpy increases for each successive electron. (b) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration. (c) End of valence electrons is marked by a big jump in ionization enthalpy. (d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.a. Ionization enthalpy increases for each successive electron.b. The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.c. End of valence electrons is marked by a big jump in ionization enthalpy.d. Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.[1]
4.A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be (i) possible at high temperature (ii) possible only at low temperature (iii) not possible at any temperature (v) possible at any temperaturei. possible at high temperatureii. possible only at low temperatureiii. not possible at any temperaturev. possible at any temperature[1]
5.Which one of the following will have the 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)i. 1 g Au (s)ii. 1 g Na (s)iii. 1 g Li (s)iv. 1 g of Cl2(g)[1]
6.In the organic compound CH2=CH-CH2-CH2-C≡CH, the pair of hybridised orbitals involved in the formation of: C2-C3 bond is: (a) sp - sp2 (b) sp - sp3 (c) sp2 - sp3 (d) sp3 - sp3a. sp - sp2b. sp - sp3c. sp2 - sp3d. sp3 - sp3[1]
7.Which of the following carbocation is most stable? (a) (CH3)3C-CH2+ (b) (CH3)3C+ (c) CH3CH2CH2+ (d) CH3CH+CH2CH3a. (CH3)3C-CH2+b. (CH3)3C+c. CH3CH2CH2+d. CH3CH+CH2CH3[1]
8.Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell? (a) Valence principal quantum number (n) (b) Nuclear charge (Z ) (c) Nuclear mass (d) Number of core electrons.a. Valence principal quantum number (n)b. Nuclear charge (Z )c. Nuclear massd. Number of core electrons.[1]
9.The enthalpies of all elements in their standard states are: (i) unity (ii) zero (iii) < 0 (iv) different for each elementi. unityii. zeroiii. < 0iv. different for each element[1]
10.The reaction: CH3CH2I + KOH(aq) → CH3CH2OH + KI is classified as : (a) electrophilic substitution (b) nucleophilic substitution (c) elimination (d) additiona. electrophilic substitutionb. nucleophilic substitutionc. eliminationd. addition[1]
11.The best and latest technique for isolation, purification and separation of organic compounds is: (a) Crystallisation (b) Distillation (c) Sublimation (d) Chromatographya. Crystallisationb. Distillationc. Sublimationd. Chromatography[1]
12.In the Lassaigne’s test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of: (a) Na4[Fe(CN)6] (b) Fe4[Fe(CN)6]3 (c) Fe2[Fe(CN)6] (d) Fe3[Fe(CN)6]4a. Na4[Fe(CN)6]b. Fe4[Fe(CN)6]3c. Fe2[Fe(CN)6]d. Fe3[Fe(CN)6]4[1]
13.ΔU° of combustion of methane is - X kJ mol^-1. The value of ΔH° is (i) = ΔU° (ii) > ΔU° (iii) < ΔU° (iv) = 0i. = ΔU°ii. > ΔU°iii. < ΔU°iv. = 0[1]
14.The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are, -890.3 kJ mol^-1 -393.5 kJ mol^-1, and -285.8 kJ mol^-1 respectively. Enthalpy of formation of CH4(g) will be (i) -74.8 kJ mol^-1 (ii) -52.27 kJ mol^-1 (iii) +74.8 kJ mol^-1 (iv) +52.26 kJ mol^-1.i. -74.8 kJ mol^-1ii. -52.27 kJ mol^-1iii. +74.8 kJ mol^-1iv. +52.26 kJ mol^-1.[1]
15.Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is : (a) B > C > Si > N > F (b) Si > C > B > N > F (c) F > N > C > B > Si (d) F > N > C > Si > Ba. B > C > Si > N > Fb. Si > C > B > N > Fc. F > N > C > B > Sid. F > N > C > Si > B[1]
Part II — Short Answer Questions 14 × 2 = 28

Answer briefly. (Answer all questions.)

16.Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn.[2]
17.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 per cent by mass. (ii) Determine the molality of chloroform in the water sample.[2]
18.The mass of an electron is 9.1 x 10^-31 kg. If its K.E. is 3.0 x 10^-25 J, calculate its wavelength.[2]
19.Identify the substance oxidised reduced, oxidising agent and reducing agent for each of the following reactions: (a) 2AgBr (s) + C6H6O2(aq) → 2Ag(s) + 2HBr (aq) + C6H4O2(aq) (b) HCHO(l) + 2[Ag (NH3)2]+(aq) + 3OH- (aq) → 2Ag(s) + HCOO-(aq) + 4NH3(aq) + 2H2O(l) (c) HCHO (l) + 2 Cu2+(aq) + 5 OH- (aq) → Cu2O(s) + HCOO-(aq) + 3H2O(l) (d) N2H4(l) + 2H2O2(l) → N2(g) + 4H2O(l) (e) Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)[2]
20.Determine the empirical formula of an oxide of iron, which has 69.9% iron and 30.1% dioxygen by mass.[2]
21.The work function for caesium atom is 1.9 eV. Calculate (a) the threshold wavelength and (b) the threshold frequency of the radiation. If the caesium element is irradiated with a wavelength 500 nm, calculate the kinetic energy and the velocity of the ejected photoelectron.[2]
22.Compare the relative stability of the following species and indicate their magnetic properties; O2, O2+, O2- (superoxide), O2^2- (peroxide)[2]
23.Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that?[2]
24.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.[2]
25.Out of benzene, m-dinitrobenzene and toluene which will undergo nitration most easily and why?[2]
26.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%[2]
27.Explain why BeH2 molecule has a zero dipole moment although the Be-H bonds are polar.[2]
28.Comment on the thermodynamic stability of NO(g), given 1/2 N2(g) + 1/2 O2(g) → NO(g); ΔrH° = 90 kJ mol^-1 NO(g) + 1/2 O2(g) → NO2(g): ΔrH°= -74 kJ mol^-1[2]
29.How much energy is required to ionise a H atom if the electron occupies n = 5 orbit? Compare your answer with the ionization enthalpy of H atom (energy required to remove the electron from n = 1 orbit).[2]
🔑 Show Answer Key — Set 1
  1. 1. (a) nuclear charge (Z ).
  2. 2. (b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.
  3. 3. (d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.
  4. 4. (v) possible at any temperature.
  5. 5. (iii) 1 g Li (s).
  6. 6. (c) sp2 - sp3.
  7. 7. (b) (CH3)3C+.
  8. 8. (c) Nuclear mass.
  9. 9. (ii) zero.
  10. 10. (b) nucleophilic substitution.
  11. 11. (d) Chromatography.
  12. 12. (b) Fe4[Fe(CN)6]3.
  13. 13. (iii) < ΔU°.
  14. 14. (i) -74.8 kJ mol^-1.
  15. 15. (c) F > N > C > B > Si.
  16. 16. Mg > Al > Zn > Fe > Cu.
  17. 17. (i) 0.0015% by mass. (ii) 1.26 x 10^-4 mol kg^-1.
  18. 18. 8.96 x 10^-7 m.
  19. 19. (a) C6H6O2 oxidised/reducing agent; AgBr reduced/oxidising agent. (b) HCHO oxidised/reducing agent; [Ag(NH3)2]+ reduced/oxidising agent. (c) HCHO oxidised/reducing agent; Cu2+ reduced/oxidising agent. (d) N2H4 oxidised/reducing agent; H2O2 reduced/oxidising agent. (e) Pb oxidised/reducing agent; PbO2 reduced/oxidising agent.
  20. 20. Fe2O3.
  21. 21. (a) 653 nm. (b) 4.59 x 10^14 s^-1. For 500 nm radiation, kinetic energy = 0.58 eV = 9.3 x 10^-20 J and velocity = 4.5 x 10^5 m s^-1.
  22. 22. Stability order: O2+ > O2 > O2- > O2^2-. O2+, O2 and O2- are paramagnetic; O2^2- is diamagnetic.
  23. 23. Mendeleev used atomic weight as the main basis, but he did not stick to it strictly when chemical properties required a different placement.
  24. 24. (a) 11.65; (b) 12.21; (c) 12.57; (d) 1.87.
  25. 25. Toluene undergoes nitration most easily.
  26. 26. 39.95 g mol^-1.
  27. 27. BeH2 is linear, so the two equal and opposite Be-H bond dipoles cancel.
  28. 28. NO(g) is thermodynamically unstable with respect to its elements and can be oxidised exothermically to NO2.
  29. 29. 0.544 eV per atom, or 8.72 x 10^-20 J per atom. This is 1/25 of the ground-state ionisation energy.
Brain Grain · braingrain.in
Chemistry — Practice Paper · Set 2
Class: 11CBSE / NCERTMax Marks: 43
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 15 × 1 = 15

Choose the correct answer. (Answer all questions.)

1.Choose the correct answer. A thermodynamic state function is a quantity (i) used to determine heat changes (ii) whose value is independent of path (iii) used to determine pressure volume work (iv) whose value depends on temperature only.i. used to determine heat changesii. whose value is independent of pathiii. used to determine pressure volume workiv. whose value depends on temperature only.[1]
2.In the modern periodic table, the period indicates the value of : (a) atomic number (b) atomic mass (c) principal quantum number (d) azimuthal quantum number.a. atomic numberb. atomic massc. principal quantum numberd. azimuthal quantum number[1]
3.For the process to occur under adiabatic conditions, the correct condition is: (i) ΔT = 0 (ii) Δp = 0 (iii) q = 0 (iv) w = 0i. ΔT = 0ii. Δp = 0iii. q = 0iv. w = 0[1]
4.Considering the elements B, Al, Mg, and K, the correct order of their metallic character is : (a) B > Al > Mg > K (b) Al > Mg > B > K (c) Mg > Al > K > B (d) K > Mg > Al > Ba. B > Al > Mg > Kb. Al > Mg > B > Kc. Mg > Al > K > Bd. K > Mg > Al > B[1]
5.The size of isoelectronic species — F-, Ne and Na+ is affected by (a) nuclear charge (Z ) (b) valence principal quantum number (n) (c) electron-electron interaction in the outer orbitals (d) none of the factors because their size is the same.a. nuclear charge (Z )b. valence principal quantum number (n)c. electron-electron interaction in the outer orbitalsd. none of the factors because their size is the same.[1]
6.Which of the following statements related to the modern periodic table is incorrect? (a) The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell. (b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell. (c) Each block contains a number of columns equal to the number of electrons that can occupy that subshell. (d) The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.a. The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell.b. The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.c. Each block contains a number of columns equal to the number of electrons that can occupy that subshell.d. The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.[1]
7.Which one of the following statements is incorrect in relation to ionization enthalpy? (a) Ionization enthalpy increases for each successive electron. (b) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration. (c) End of valence electrons is marked by a big jump in ionization enthalpy. (d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.a. Ionization enthalpy increases for each successive electron.b. The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.c. End of valence electrons is marked by a big jump in ionization enthalpy.d. Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.[1]
8.A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be (i) possible at high temperature (ii) possible only at low temperature (iii) not possible at any temperature (v) possible at any temperaturei. possible at high temperatureii. possible only at low temperatureiii. not possible at any temperaturev. possible at any temperature[1]
9.Which one of the following will have the 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)i. 1 g Au (s)ii. 1 g Na (s)iii. 1 g Li (s)iv. 1 g of Cl2(g)[1]
10.In the organic compound CH2=CH-CH2-CH2-C≡CH, the pair of hybridised orbitals involved in the formation of: C2-C3 bond is: (a) sp - sp2 (b) sp - sp3 (c) sp2 - sp3 (d) sp3 - sp3a. sp - sp2b. sp - sp3c. sp2 - sp3d. sp3 - sp3[1]
11.Which of the following carbocation is most stable? (a) (CH3)3C-CH2+ (b) (CH3)3C+ (c) CH3CH2CH2+ (d) CH3CH+CH2CH3a. (CH3)3C-CH2+b. (CH3)3C+c. CH3CH2CH2+d. CH3CH+CH2CH3[1]
12.Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell? (a) Valence principal quantum number (n) (b) Nuclear charge (Z ) (c) Nuclear mass (d) Number of core electrons.a. Valence principal quantum number (n)b. Nuclear charge (Z )c. Nuclear massd. Number of core electrons.[1]
13.The enthalpies of all elements in their standard states are: (i) unity (ii) zero (iii) < 0 (iv) different for each elementi. unityii. zeroiii. < 0iv. different for each element[1]
14.The reaction: CH3CH2I + KOH(aq) → CH3CH2OH + KI is classified as : (a) electrophilic substitution (b) nucleophilic substitution (c) elimination (d) additiona. electrophilic substitutionb. nucleophilic substitutionc. eliminationd. addition[1]
15.The best and latest technique for isolation, purification and separation of organic compounds is: (a) Crystallisation (b) Distillation (c) Sublimation (d) Chromatographya. Crystallisationb. Distillationc. Sublimationd. Chromatography[1]
Part II — Short Answer Questions 14 × 2 = 28

Answer briefly. (Answer all questions.)

16.Write the complete symbol for the atom with the given atomic number (Z) and atomic mass (A): (i) Z = 17, A = 35 (ii) Z = 92, A = 233 (iii) Z = 4, A = 9[2]
17.Write chemical equations for combustion reaction of the following hydrocarbons: (i) Butane (ii) Pentene (iii) Hexyne (iv) Toluene[2]
18.The ionization constant of dimethylamine is 5.4 x 10^-4. Calculate its degree of ionization in its 0.02M solution. What percentage of dimethylamine is ionized if the solution is also 0.1M in NaOH?[2]
19.Which of the two: O2NCH2CH2O- or CH3CH2O- is expected to be more stable and why?[2]
20.What is the pH of 0.001M aniline solution? The ionization constant of aniline can be taken from Table 6.7. Calculate the degree of ionization of aniline in the solution. Also calculate the ionization constant of the conjugate acid of aniline.[2]
21.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 Δi H than B (ii) O has lower Δi H than N and F?[2]
22.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.[2]
23.What are electrophiles and nucleophiles ? Explain with examples.[2]
24.Discuss the chemistry of Lassaigne’s test.[2]
25.An electron is in one of the 3d orbitals. Give the possible values of n, l and ml for this electron.[2]
26.Define the bond length.[2]
27.Suggest a list of the substances where carbon can exhibit oxidation states from -4 to +4 and nitrogen from -3 to +5.[2]
28.Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (a) Lithium and oxygen (b) Magnesium and nitrogen (c) Aluminium and iodine (d) Silicon and oxygen (e) Phosphorus and fluorine (f) Element 71 and fluorine[2]
29.Calculate the mass of sodium acetate (CH3COONa) required to make 500 mL of 0.375 molar aqueous solution. Molar mass of sodium acetate is 82.0245 g mol–1.[2]
🔑 Show Answer Key — Set 2
  1. 1. (ii) whose value is independent of path.
  2. 2. (c) principal quantum number.
  3. 3. (iii) q = 0.
  4. 4. (d) K > Mg > Al > B.
  5. 5. (a) nuclear charge (Z ).
  6. 6. (b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.
  7. 7. (d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.
  8. 8. (v) possible at any temperature.
  9. 9. (iii) 1 g Li (s).
  10. 10. (c) sp2 - sp3.
  11. 11. (b) (CH3)3C+.
  12. 12. (c) Nuclear mass.
  13. 13. (ii) zero.
  14. 14. (b) nucleophilic substitution.
  15. 15. (d) Chromatography.
  16. 16. (i) 35Cl. (ii) 233U. (iii) 9Be.
  17. 17. (i) 2C4H10 + 13O2 → 8CO2 + 10H2O; (ii) 2C5H10 + 15O2 → 10CO2 + 10H2O; (iii) 2C6H10 + 17O2 → 12CO2 + 10H2O; (iv) C7H8 + 9O2 → 7CO2 + 4H2O.
  18. 18. Degree of ionization in 0.02 M solution = 0.151; in 0.1 M NaOH, 0.54% is ionized.
  19. 19. O2NCH2CH2O- is more stable.
  20. 20. pH = 7.82; degree of ionization = 6.53 x 10^-4; Ka of conjugate acid = 2.34 x 10^-5.
  21. 21. (i) Be has a stable filled 2s2 subshell, while B loses a 2p electron more easily. (ii) O has paired-electron repulsion in 2p4, while N has stable half-filled 2p3; F has higher effective nuclear charge.
  22. 22. (a) Chlorobenzene > p-nitrochlorobenzene > 2,4-dinitrochlorobenzene. (b) Toluene > p-nitrotoluene > p-dinitrobenzene.
  23. 23. Electrophiles are electron-pair acceptors; nucleophiles are electron-pair donors.
  24. 24. Lassaigne's test converts covalently bonded N, S and halogens into ionic sodium salts, which are then detected by characteristic reactions.
  25. 25. n = 3, l = 2, and ml = -2, -1, 0, +1 or +2.
  26. 26. Bond length is the equilibrium distance between the nuclei of two bonded atoms in a molecule.
  27. 27. Carbon: CH4 (-4), CH3Cl (-2), CH2Cl2 (0), CHCl3 (+2), CCl4 (+4). Nitrogen: NH3 (-3), N2H4 (-2), NH2OH (-1), N2 (0), N2O (+1), NO (+2), HNO2 (+3), NO2 (+4), HNO3 (+5).
  28. 28. (a) Li2O. (b) Mg3N2. (c) AlI3. (d) SiO2. (e) PF3 and PF5. (f) LuF3.
  29. 29. 15.38 g.
Brain Grain · braingrain.in
Chemistry — Practice Paper · Set 3
Class: 11CBSE / NCERTMax Marks: 43
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 15 × 1 = 15

Choose the correct answer. (Answer all questions.)

1.In the Lassaigne’s test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of: (a) Na4[Fe(CN)6] (b) Fe4[Fe(CN)6]3 (c) Fe2[Fe(CN)6] (d) Fe3[Fe(CN)6]4a. Na4[Fe(CN)6]b. Fe4[Fe(CN)6]3c. Fe2[Fe(CN)6]d. Fe3[Fe(CN)6]4[1]
2.ΔU° of combustion of methane is - X kJ mol^-1. The value of ΔH° is (i) = ΔU° (ii) > ΔU° (iii) < ΔU° (iv) = 0i. = ΔU°ii. > ΔU°iii. < ΔU°iv. = 0[1]
3.The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are, -890.3 kJ mol^-1 -393.5 kJ mol^-1, and -285.8 kJ mol^-1 respectively. Enthalpy of formation of CH4(g) will be (i) -74.8 kJ mol^-1 (ii) -52.27 kJ mol^-1 (iii) +74.8 kJ mol^-1 (iv) +52.26 kJ mol^-1.i. -74.8 kJ mol^-1ii. -52.27 kJ mol^-1iii. +74.8 kJ mol^-1iv. +52.26 kJ mol^-1.[1]
4.Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is : (a) B > C > Si > N > F (b) Si > C > B > N > F (c) F > N > C > B > Si (d) F > N > C > Si > Ba. B > C > Si > N > Fb. Si > C > B > N > Fc. F > N > C > B > Sid. F > N > C > Si > B[1]
5.Choose the correct answer. A thermodynamic state function is a quantity (i) used to determine heat changes (ii) whose value is independent of path (iii) used to determine pressure volume work (iv) whose value depends on temperature only.i. used to determine heat changesii. whose value is independent of pathiii. used to determine pressure volume workiv. whose value depends on temperature only.[1]
6.In the modern periodic table, the period indicates the value of : (a) atomic number (b) atomic mass (c) principal quantum number (d) azimuthal quantum number.a. atomic numberb. atomic massc. principal quantum numberd. azimuthal quantum number[1]
7.For the process to occur under adiabatic conditions, the correct condition is: (i) ΔT = 0 (ii) Δp = 0 (iii) q = 0 (iv) w = 0i. ΔT = 0ii. Δp = 0iii. q = 0iv. w = 0[1]
8.Considering the elements B, Al, Mg, and K, the correct order of their metallic character is : (a) B > Al > Mg > K (b) Al > Mg > B > K (c) Mg > Al > K > B (d) K > Mg > Al > Ba. B > Al > Mg > Kb. Al > Mg > B > Kc. Mg > Al > K > Bd. K > Mg > Al > B[1]
9.The size of isoelectronic species — F-, Ne and Na+ is affected by (a) nuclear charge (Z ) (b) valence principal quantum number (n) (c) electron-electron interaction in the outer orbitals (d) none of the factors because their size is the same.a. nuclear charge (Z )b. valence principal quantum number (n)c. electron-electron interaction in the outer orbitalsd. none of the factors because their size is the same.[1]
10.Which of the following statements related to the modern periodic table is incorrect? (a) The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell. (b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell. (c) Each block contains a number of columns equal to the number of electrons that can occupy that subshell. (d) The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.a. The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell.b. The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.c. Each block contains a number of columns equal to the number of electrons that can occupy that subshell.d. The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.[1]
11.Which one of the following statements is incorrect in relation to ionization enthalpy? (a) Ionization enthalpy increases for each successive electron. (b) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration. (c) End of valence electrons is marked by a big jump in ionization enthalpy. (d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.a. Ionization enthalpy increases for each successive electron.b. The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.c. End of valence electrons is marked by a big jump in ionization enthalpy.d. Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.[1]
12.A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be (i) possible at high temperature (ii) possible only at low temperature (iii) not possible at any temperature (v) possible at any temperaturei. possible at high temperatureii. possible only at low temperatureiii. not possible at any temperaturev. possible at any temperature[1]
13.Which one of the following will have the 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)i. 1 g Au (s)ii. 1 g Na (s)iii. 1 g Li (s)iv. 1 g of Cl2(g)[1]
14.In the organic compound CH2=CH-CH2-CH2-C≡CH, the pair of hybridised orbitals involved in the formation of: C2-C3 bond is: (a) sp - sp2 (b) sp - sp3 (c) sp2 - sp3 (d) sp3 - sp3a. sp - sp2b. sp - sp3c. sp2 - sp3d. sp3 - sp3[1]
15.Which of the following carbocation is most stable? (a) (CH3)3C-CH2+ (b) (CH3)3C+ (c) CH3CH2CH2+ (d) CH3CH+CH2CH3a. (CH3)3C-CH2+b. (CH3)3C+c. CH3CH2CH2+d. CH3CH+CH2CH3[1]
Part II — Short Answer Questions 14 × 2 = 28

Answer briefly. (Answer all questions.)

16.Define hydrogen bond. Is it weaker or stronger than the van der Waals forces?[2]
17.Explain, giving reasons, which of the following sets of quantum numbers are not possible. (a) n = 0, l = 0, ml = 0, ms = + 1/2 (b) n = 1, l = 0, ml = 0, ms = - 1/2 (c) n = 1, l = 1, ml = 0, ms = + 1/2 (d) n = 2, l = 1, ml = 0, ms = - 1/2 (e) n = 3, l = 3, ml = -3, ms = + 1/2 (f) n = 3, l = 1, ml = 0, ms = + 1/2[2]
18.Explain with the help of suitable example polar covalent bond.[2]
19.Write the significance/applications of dipole moment.[2]
20.Depict the galvanic cell in which the reaction Zn(s) + 2Ag+(aq) → Zn2+(aq) +2Ag(s) takes place, Further show: (i) which of the electrode is negatively charged, (ii) the carriers of the current in the cell, and (iii) individual reaction at each electrode.[2]
21.Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as: CH3COOH (l) + C2H5OH (l) ⇌ CH3COOC2H5 (l) + H2O (l) (i) Write the concentration ratio (reaction quotient), Qc, for this reaction (note: 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?[2]
22.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.[2]
23.The diameter of zinc atom is 2.6 A. Calculate (a) radius of zinc atom in pm and (b) number of atoms present in a length of 1.6 cm if the zinc atoms are arranged side by side lengthwise.[2]
24.A certain particle carries 2.5 x 10^-16C of static electric charge. Calculate the number of electrons present in it.[2]
25.The Mn3+ ion is unstable in solution and undergoes disproportionation to give Mn2+, MnO2, and H+ ion. Write a balanced ionic equation for the reaction.[2]
26.Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume? (a) PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) (b) CaO (s) + CO2 (g) ⇌ CaCO3 (s) (c) 3Fe (s) + 4H2O (g) ⇌ Fe3O4 (s) + 4H2 (g)[2]
27.The concentration of hydrogen ion in a sample of soft drink is 3.8 x 10^-3 M. What is its pH?[2]
28.The ionization constant of propanoic acid is 1.32 x 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?[2]
29.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.[2]
🔑 Show Answer Key — Set 3
  1. 1. (b) Fe4[Fe(CN)6]3.
  2. 2. (iii) < ΔU°.
  3. 3. (i) -74.8 kJ mol^-1.
  4. 4. (c) F > N > C > B > Si.
  5. 5. (ii) whose value is independent of path.
  6. 6. (c) principal quantum number.
  7. 7. (iii) q = 0.
  8. 8. (d) K > Mg > Al > B.
  9. 9. (a) nuclear charge (Z ).
  10. 10. (b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.
  11. 11. (d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.
  12. 12. (v) possible at any temperature.
  13. 13. (iii) 1 g Li (s).
  14. 14. (c) sp2 - sp3.
  15. 15. (b) (CH3)3C+.
  16. 16. A hydrogen bond is the attractive interaction between H bonded to a highly electronegative atom and another electronegative atom such as F, O or N. It is stronger than van der Waals forces but weaker than covalent bonds.
  17. 17. Not possible: (a), (c) and (e). Possible: (b), (d) and (f).
  18. 18. A polar covalent bond is a covalent bond in which the shared electron pair is drawn more toward the more electronegative atom, giving partial charges. Example: H-Cl.
  19. 19. Dipole moment helps determine molecular polarity, distinguish molecular shapes, compare ionic character and identify bond/molecular symmetry.
  20. 20. Cell: Zn(s)|Zn2+(aq)||Ag+(aq)|Ag(s). The zinc electrode is negative. Electrons carry current in the external circuit and ions carry current through the electrolyte/salt bridge. Anode: Zn → Zn2+ + 2e-. Cathode: Ag+ + e- → Ag.
  21. 21. (i) Qc = [CH3COOC2H5][H2O]/([CH3COOH][C2H5OH]); (ii) Kc = 3.92; (iii) equilibrium has not been reached, and the reaction proceeds forward.
  22. 22. (a) They are isoelectronic, each having 10 electrons. (b) Al3+ < Mg2+ < Na+ < F- < O2- < N3-.
  23. 23. (a) 130 pm. (b) 6.15 x 10^7 atoms.
  24. 24. 1.56 x 10^3 electrons, approximately 1560 electrons.
  25. 25. 2Mn3+ + 2H2O → Mn2+ + MnO2 + 4H+.
  26. 26. (a) Increase; (b) decrease; (c) remain same.
  27. 27. pH = 2.42.
  28. 28. In pure solution, α = 0.0162 and pH = 3.09. In 0.01 M HCl, α = 1.32 x 10^-3.
  29. 29. The reaction occurs because Xe(VIII) in XeO6^4- is reduced and F- is oxidised; Na4XeO6 is a strong oxidising agent.

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