Chemistry-80.POTENTIAL DISCOVERY TEST

CHEMISTRY Time: 90 minutes Maximum Marks: 150 Note: i) This question paper contains 50 Objective type questions. Each question has only one correct answer. For every correct answer 3 marks will be awarded and 1 mark will be deducted for each wrong answer. ii). Mark your answer in the scoring sheet provided separately. iii) Use of Calculator/Logarithmic table is NOT PERMITTED iv) Useful Data: Gas Constant R = 8.314 J K1 mol1 = 0.0821 Lit atm K1 mol1 = 1.987  2 Cal K1 mol1 g = 10 m/sec2 Avogadro’s Number Na = 6.023  1023 1 Faraday = 96500 Coulomb 1 calorie = 4.2 Joule Atomic No: Ca = 20, C = 6, O = 8, K = 19, Cl = 17, N = 7, S = 16, Na = 11. Cu = 29, Co =27, Mn = 25. Atomic Masses: Ag = 108, Mn = 55, C = 12, O = 16, K = 39, N = 14, Na = 23, H = 1, I = 127. Name of the student : Registration Number : Date of Examination : Centre 1. The correct electronic configuration of nitrogen is (A) 1s2 2s2 (B) 1s2 2s2 (C) 1s22s2 (D) 1s2 2. The volume of a gas is reduced to half of its original volume the pressure will be (A) reduced by half (B) increased by two times (C) increased by four times (D) not changed 3. The rate of which a substance reacts depends on its (A) Atomic weight (B) Equivalent weight (C) Molecular weight (D) Active mass 4. The oxidation number of Cr in CrO5 is (A) + 10 (B) + 7 (C) +6 (D) + 4 5. The I.U.P.A.C. name of CH3OC¬2H5 is (A) Ethoxymethane (B) Methoxyethane (C) Methyl ethyl ether (D) Ethyl methyl ether 6. A p-orbital can accommodate (A) 4 electrons (B) 6 electrons (C) 2 electrons with parallel spins (D) 2 electrons with opposite spins 7. Which of the following will conduct electricity? (A) Crystalline NaCl (B) Fused NaCl (C) Molten sulphur (D) Diamond 8. When two ice cubes are pressed over each other, they unite to form one cube. Which of the following forces is responsible to hold them together? (A) Hydrogen bond formation (B) Van der Waal's forces (C) Covalent attraction (D) Dipole interaction 9. A chemical reaction is at equilibrium when the rate of forward and backward reactions are (A) Unequal (B) Constant (C) Equal (D) Increasing space for rough work 10. Which of the following gas has the highest heat of combustion (A) Methane (B) Ethane (C) Ethylene (D) Acetylene 11. One faraday is equal to (A) 69500 coulomb (B) 96500 coulomb (C) 96500 coulombs approximately (D) None of the above 12. Avogadro’s number represents the number of atoms in (A) 320g of sulphur (B) 32g of oxygen (C) 12g of C12 (D) 12.7g of Iodine 13. H2 +  H2O when we take 2 moles of H2 & 2 moles of O2 the moles of water formed will be. (A) 2 moles (B) 3 moles (C) 1.5 moles (D) 1 mole 14. CxHyCl is an alkyl halide the relation between x & y is (A) x = y (B) x = y + 2 (C) y = 2x + 1 (D) x = 2y + 1 15. When an electropositive atom combines with an electronegative atom it forms (A) Ionic Bond (B) Covalent Bond (C) Coordinate Bond (D) They will not combine 16. A has 2 electrons in the outer most shell and B is having 5 electrons in the outer most shell. The ionic compound formed between the two atoms will be (A) A3B2 (B) A2B¬2 (C) AB (D) A2B3 17. In N2 molecule two N-atoms are bounded by (A) 2 covalent bonds (B) 2 ionic bonds (C) 3 covalent bonds (D) 1 ionic and 2 covalent bonds 18. The last electron an element having atomic number 16 will be in (A) 3rd shell (B) 4th shell (C) 2nd shell (D) 1st shell space for rough work 19. An electron releases energy when it (A) moves from lower to higher energy level (B) moves from higher energy level to lower energy level. (C) revolves in the shell (D) It will never release the energy. 20. SO2 can act as (A) oxidizing agent (B) reducing agent (C) both (D) none 21. The IUPAC name of oxalic acid is (A) propanoic acid (B) ethanoic acid (C) ethan-1,2-dioic acid (D) eth1, 2-oic acid 22 Find the ratio of number of molecules contained in 1gm of NH3 and 1 gm N2 (A) 20 : 17 (B) 28 : 17 (C) 17 : 28 (D) 14 : 17 23. Under what conditions of temperature and pressure, the gas have maximum density? (A) 1 atm 0°C (B) 1 atm, 273° C (C) 2 atm, 0°C (D) 2 atm, 273°C 24. Which of the following arrangements of electrons is most likely to be stable. (A) 3d 4s 3d 4s (A) ­ ­ ­ ­ ­ ­ (B) ­¯ ­ ­ ­ ­ 3d 4s 3d 4s (C) ­ ­ ­ ­ ­ ¯ (D) ­ ­ ­ ­ ­¯ 25. Two vessels of equal volume contain two gases A and B separately at 1 atm and 4 atm respectively. If the vessels are connected through a narrow tube of negligible volume, what is the total pressure of gaseous mixture? (A) 1 atm (B) 4 atm (C) 5 atm (D) 2.5 atm 26. [N2,CO, CN–] are example of (A) Isoelectronic (B) Isotonic (C) Isotopes (D) Isobars space for rough work 27. The ionization potential for an electron in ground state of the hydrogen atom is 13.6 eV. What would be the ionization potential for the electron in the first excited state of H atom. (A) 13.6 eV (B) 6.8 eV (C) 3.4eV (D) 27.2 eV 28. A gas mixture contains 20% by weight of H2 and 80% by weight of O2. The total pressure is 1 atm. What is the partial pressure of H2? (A) 0.5 atm (B) 0.67 atm (C) 0.75 atm (D) 0.80 atm 29. Velocity of an electron in the second orbit of He+ ion is (A) 2.18 ´ 108 m/sec (B) 2.18 ´ 107 m/sec (C) 2.18 ´ 106 m/sec (D) 2.18 ´ 105 m/sec 30. The important principle which does not help in assigning the electronic configuration of atoms is (A) Aufbau principle (B) Hund’s rule (C) Heisenberg’s uncertainty principle (D) Paul’s exclusion principle 31. Equal masses of gaseous H2 and N2 are present in two flasks of same capacity and at constant temperature. What is ratio of number of molecules of H2 and N2? (A) 14 : 1 (B) 1 : 1 (C) 28 : 1 (D) 1.5 :1 32. Which one is the strongest base? (A) HOCl (B) HOClO (C) HOClO2 (D) HOClO3 33. Conjugate acid of is (A) NH3 (B) H2O (C) (D) 34. The unit of the rate of reaction is the same as that of the rate constant for a (A) zero order reaction (B) first order reaction (C) second order reaction (D) half order reaction space for rough work 35. If E1, E2 and E3 represent respectively the kinetic energies of an electron, an alpha particle and a proton,each having same de-Broglie wavelength, then: (A) E1  E3  E2 (B) E2  E3  E1 (C) E1  E2  E3 (D) E1 = E2 = E3 36. Non directional orbital is (A) 3s (B) 4f (C) 4d (D) 4p 37. One requires energy En to remove a nucleon and energy Ee to remove an electron from the orbit of an atoms, thus: (A) En = Ee (B) En  Ee (C) En  Ee (D) En  Ee 38. If 10–17 J of light energy is needed by the interior of human eye to see an object, the photons of green light ( = 550 nm) needed to see the object are: (A) 27 (B) 28 (C) 29 (D) 30 39. Which species does not show paramagnetism : (A) O2 (B) (C) (D) 40. H—B—H bond angle in is : (A) 180° (B) 120° (C) 109° (D) 90° 41. The total number of valence electrons in 4.2 gm of ion are (A) 2.2 N (B) 4.2 N (C) 1.6 N (D) 3.2 N 42. Among the following molecules, in which does bromine show the maximum oxidation number (A) Hg2(BrO3)2 (B) Br—Cl (C) KBrO4 (D) Br2 space for rough work 43. A compound contains atom A,B and C, the oxidation number of A = +2, that of B = +5 and that of C = –2. The possible formula of the compound is (A) ABC2 (B) A2(BC3)2 (C) A3(BC4)2 (D) A3(B4C)2 44. How much water is added to dilute 10 ml of 10N HCl to make it decinormal (A) 990 ml (B) 1010 ml (C) 100 ml (D) 1000 ml 45. Which sample contains largest number of atoms (A) 1 mg of C4H10 (B) 1 mg of N2 (C) 1 mg of Na (D) 1 ml of water 46. The process requiring absorption of energy is (A) F  F– (B) H  H– (C) Cl  Cl– (D) O  O2– 47. Three isotopes of an element have mass number M, (M+1) and (M+2). If the mean mass number is (M+0.5), which of the following ratio may be accepted for M, (M+1) and (M+2) that order (A) 1 : 1 : 1 (B) 4 : 1 : 1 (C) 3 : 2 : 1 (D) 2 : 1 : 1 48. If for two gases of molecular weights MA and MB at temperature TA and TB, TAMB = TBMA, then which property has the same magnitude for both the gases (a) Density (b) Pressure (c) KE per mol (d) rms speed 49. How many atoms are contained in a mole of Ca(OH)2 (a) 30 N (b) 5N (c) 3N (d) None 50. The configuration 1s22s22p53s1 shows (A) Ground state of fluorine atom (B) Excited state of fluorine atom (C) Excited state of neon atom (D) Excited state of oxygen atom space for rough work ANSWERS 1. B 2. B 3. D 4. C 5 B 6. D 7. B 8. A 9. C 10. B 11. C 12. C 13. A 14. C 15. A 16. A 17. C 18. A 19. B 20. C 21. C 22. B 23. C 24. A 25. D 26. A 27. C 28. D 29. C 30. C 31. A 32. D 33. A 34. A 35. A 36. A 37. C 38. B 39. C 40. C 41. C 42. D 43. C 44. A 45. D 46. B 47. B 48. D 49. B 50. C 6