Chemistry 11 Solved Past Papers Repeated Important MCQS Notes, Most important mcqs revised in every year in exams.
1. In Al2O3, the ratio between the ions is:
(A) 1:2 (B) 2:1 (C) 2:3 (D) 3:2
2. The number of atoms in 1.79 g of gold and _____ g of sodium are equal.
(A) 0.23 (B) 23 (C) 230 (D) 2300
3. Number of isotopes of oxygen is:
(A) Two (B) Three (C) Four (D) Five
4. A beaker contains 9 g of water. The number of H-atoms in it is:
(A) NA of atom (B) 2 × NA of atoms (C) N of atoms 12 A (D) 3 × NA of atoms
5. I gram formula of NaCl is equal to:
(A) 58.5g (B) 23.5g (C) 35.5g (D) 12g
6. The calculation based on balanced chemical equation is called:
(A) Complex calculation (B) Stoichiometric calculation
(C) Non-stoichiometric calculation (D) None of these
7. The branch of chemistry which tells us the quantitative relationship between reactants and products is called:
(A) Stoichiometry (B) Thermometry (C) Organic chemistry (D) Physical chemistry
8. The ratio of actual yield to theoretical yield multiplied by 100 is called:
(A) complex yield (B) Experimental yield (C) %age yield (D) None of these
9. A limiting reactant is the one which:
(A) Is taken in lesser quantity in grams as compared to other reactants.
(B) Is taken in lesser quantity in volume as compared to the other
(C) Carries the maximum amount of the product which is required.
(D) Gives the minimum amount of the product under consideration.
10. Gooch crucible is made of:
(A) Glass (B) Paper (C) Teflon (D) Procelain
11. The substance used for decolourization of crystalline substance is:
(A) P2O5 (B) Chloroform (C) Animal charcoal (D) Soda ash
12. During the process of crystallization, the hot saturated solution:
(A) Is cooled very slowly to get large sized crystals
(B) Is cooled at moderate rate to get medium sized crystals
(C) Is evaporated to get the crystals of the product
(D) Is mixed with an immiscible liquid to get the pure crystals of the product.
13. Which one is not example of a sublimate?
(A) Ammonium chloride (B) Iodine (C) NaCl (D) Benzoic acid
14. Which of the following compounds do not show process of sublimation?
(A) Ammonium chloride (B) Iodine (C) Naphthalene (D) Carbon tetra chloride
15. The solvent extraction technique is particularly useful when the product is:
(A) Volatile and thermally unstable (B) Volatile and thermally stable
(C) Non volatile and thermally stable (D) Non volatile and thermally unstable
16. Solvent extraction method is particularly useful technique for separation when the product to be separated is:
(A) Non-volatile or thermally unstable (B) Volatile or thermally stable
(C) Non-volatile or thermally stable (D) Volatile or thermally unstable
17. Chromatography in which the stationary phase is a solid is classified as:
(A) Partition chromatography (B) Gas Chromatography (C) Adsorption Chromatography (D) Thin layer Chromatography
18. A filtration process could be very time consuming if it were not aided by a gentle suction, which is developed:
(A) If the paper covers the funnel up to its circumference (B) If the paper has got small sized pores in it
(C) If the stem of the funnel is large so that it dips into the filtrate (D) If the paper fits tightly
19. The unit millibar is commonly used by:
(A) Meteorologists (B) Astronauts (C) Engineers (D) Dalton
20. The sum of mole fraction of gas in a mixture of gases is:
(A) Always more than one (B) Always less then one
(C) Always one (D) May be less ore more than one
21. The number of unit cell parameters are:
(A) 2 (B) 4 (C) 6 (D) 8
22. Pressure remaining constant at which temperature the volume of a gas will become twice of what it is at 0 : oC
(A) 546 o C (B) 200 o C (C) 546 K (D) 273 K
23. Which of the following will have highest rate of diffusion?
(A) O2 (B) CO2 (C) NH3 (D) SO2
24 .Oxygen molecule is heavier than hydrogen by:
(A) 1 time (B) 8 times (C) 16 times (D) 32 times
25. The highest temperature at which a substance can exist as liquid at its critical pressure is:
(A) Absolute zero (B) Consulate temperature (C) Critical temperature (D) Transition temperature
26. The sun is a _____ ball of plasma heated by nuclear fusion process.
(A) 1.5 million kilometer (B) 1.5 billion bilometer (C) 3 million kilometer (D) None of these
27. Which of the following will have the same number of molecules at STP?
(A) 280 cm3 of CO2 and 280 cm3 of N2O (B) 11.2 dm3 of O2 and 32 g of O2
(C) 44 g of CO2 and 11.2 dm3 of CO (D) 28 g of N2 and 5.6 dm of oxygen 3
28. Acetone and chloroform are soluble in each other due to:
(A) Intermolecular hydrogen bonding (B) Dipole-dipole interaction
(C) Instantaneous dipoles (D) All of the above
29. In order to mention the B.P. of water at 110 C, the external pressure should be: o
(A) between 760 torr and 1200 torr (B) between 200 torr and 760 torr
(C) 765 torr (D) any value of pressure
30. Allotropy is the property of:
(A) Compound (B) Element (C) Atom (D) Mixture
31. Transition temperature of KNO3 is:
(A) 13.2 C o
(B) 95.5 C o
(C) 128 C o
(D) 32.2 C o
32. The number of unit cell parameters are:
(A) 2 (B) 4 (C) 6 (D) 8
33. If a ≠ b ≠ c and α = γ = 90 then crystal system is: o
, β ≠ 90 degree
(A) Monoclinic (B) Diclinic (C) Triclinic (D) Polyclinic
34. In the monoclinic crystal system, bond axes are:
(A) a = b = c (B) a = b ≠ c (C) a ≠ b = c (D) a ≠ b ≠ c
35. Crystal of diamond is:
(A) Ionic (B) Covalent (C) Molecular (D) Metallic
36. When water freezes at 0 C, its density decreases due to: o
(A) Cubic structure of ice (B) Empty spaces present in the structure of ice
(C) Change of bond lengths (D) Change of bond angles
37. When fast neutron carries nuclear reaction with nitrogen it ejects particles:
(A) α
(B) β
(C) γ
(D) δ
38. The nature of positive rays depends on:
(A) The nature of electrode (B) The nature of discharge tube (C) The nature of residual gas (D) All of above
39. In the ground state of an atom, the electron is present:
(A) In the nucleus (B) In the second shell (C) Nearest to the nucleus (D) Farthest from the nucleus
40. Lyman series lies in spectral region:
(A) Infrared (B) Ultra violet (C) Visible (D) None of these
41. De-Broglie equation is represented by:
(A) h =λmv (B) m =hλv
(C) m =λhv (D) λ =hmv
42. Which equation correctly presents the Heisenberg’s uncertainty principle?
(A) △×. △p =h4π
(B) △×. △p >h4π
(C) △×. △p ≥h4π
(D) △×. △p ≤h4π
43. The value of quantum number in n = 1 , 2 , 3 , 4 , 5 ……. For:
(A) principal quantum number (B) azimuthal quantum number (C) magnetic quantum number (D) spin quantum number
44. When 5d orbital is completed then entering electron goes into:
(A) 6s (B) 6p (C) 6d (D) 6f
45. Rutherford’s model of atom failed because:
(A) the atom did not have a nucleus and electrons (B) it did not account for the attraction between protons and neutrons
(C) it did not account for stability of the atom (D) there is actually no space between the nucleus and the electrons
46. Which compound does not obey the octet rule?
(A) NH3 (B) BCl3 (C) H2O (D) CH4
47. Which of the following molecule obey octet rule?
(A) BF3 (B) BCl3 (C) NH3 (D) SF6
48. The covalent radius of Cl-atom is:
(A) 99.4pm (B) 80pm (C) 70pm (D) 66.4pm
49. Minimum amount of energy required to remove an electron from its gaseous atom is called:
(A) Ionization energy (B) Electron – Affinity (C) Oxidation (D) Reduction
50. The shape of SnCl2 molecule is:
(A) Linear (B) Angular (C) Trigonal planar (D) Tetrahedral
1. C 2. A 3. B 4. C 5. A 6. A 7. C 8. D 9. D 10. C
11.B 12. C 13. D 14. A 15. D 16. 17. C 18. D 19. A 20. C
21. C 22. C 23. C 24. C 25. C 26. A 27. A 28. A 29. A 30. B
31. C 32. A C 33. D 34. C 35. 36. B 37. A 38. C 39. C 40.B
41. D 42. C 43. A 44. B 45. C 46. B 47. C 48. A 49. A 50. C