TEST OF CHEMISTRY. 1. 2H 2 O H 3 O + + OH, Kw = at 25 C, hence Ka is (a) (b) (c) (d)

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1 TEST OF CHEMISTRY 1. 2H 2 O H 3 O + + OH, Kw = at 25 C, hence Ka is (a) (b) (c) (d) Identify the correct order of acidic strengths of CO 2, CuO, CaO, H 2 O (a) CaO < CuO < H 2 O < CO 2 (b) H 2 O < CuO < CaO < CO 2 (c) CaO < H 2 O < CuO < CO 2 (d) H 2 O < CO 2 < CaO < CuO 3. The compound that does not act as Lewis acid (a) AlCl 3 (b) BF 3 (c) NH 3 (d) FeCl 3 4. Which of the following mixture is not a buffer? (a) NH 3 + NH 4 Cl (b) HC 2 H 3 O 2 + NaOH in a 1 : 1mole ratio (c) NH 3 + HCl in a 2 : 1 mole ratio (d) HC 2 H 3 O 2 + NaOH in a 2 : 1mole ratio 5. The precipitate of CaF 2 (Ksp = ) is obtained when equal volumes of the following are mixed (a) 10 4 M Ca M F (b) 10 2 M Ca M F (c) 10 5 M Ca M F (d) 10 3 M Ca M F 6. How many grams of CaC 2 O 4 will dissolve in distilled water to make one litre of saturated solution? (Ksp of CaC 2 O 4 is mol 2 lit 2 ) (a) g (b) g (c) g (d) g 7. The compound insoluble in acetic acid is (a) calcium oxide (b) calcium carbonate (c) calcium oxalate (d) calcium hydroxide 8. In the following reaction, [Cu(H 2 O) 3 OH] + +[Al(H 2 O) 6 ] 3+ [Cu(H 2 O) 4 ] 2+ + [Al(H 2 O) 5 OH] 2+ (a) A is an acid, B is the base (b) A is a base and B is the acid (c) C is the conjugate acid of A and D is the conjugate base of B (d) C is the conjugate base of A and D is the conjugate base of B. 9. Which one is the strongest acid? (a) ClO 3 (OH) (b) ClO 2 (OH) (c) SO (OH) 2 (d) HCOO

2 10. The solubility of A 2 X 3 is y mole dm 3. Its solubility product is (a) 6y 4 (b) 64 y 4 (c) 36 y 5 (d) 108 y The pka of acetylsalicylic acid (aspirin) is 3.5. The ph of gastric juice in human stomach is about 2 3 and the ph in the small intestine is about 8. Aspirin will be (a) unionized in the small in testine and in the stomach (b) completely ionized in the small intestin and in the stomach (c) ionized in the stomach and almost un ionized in the small intestine (d) ionizedin the small intestine and almost unionized in the stomach 12. HCN behaves as a very weak acid in aqeous medium where as it acts as a strong acid in liquid ammonia because (a) Electronegativity of oxygen is greater than that of nitrogen (b) Ionization energy of oxygen is less than that of nitrogen (c) Proton affinity of water is less than that of ammonia (d) Dipole moment of water is greater than that of ammonia 13. Amongst Ni(CO) 4, [Ni(CN) 4 ] 2 and NiCl 2 4 : (a) Ni (CO) 4 and NiCl 2 4 are diamagnetic and [Ni(CN) 4 ] 2 is paramagnetic (b) NiCl 2 4 and [Ni(CN) 4 ] 2 are dimagnetic and Ni(CO) 4 is paramagnetic (c) Ni(CO) 4 and [Ni(CN) 4 ] 2 are dimagnetic and NiCl 2 4 is paramagnetic (d) Ni(CO) 4 is dimagnetic and NiCl 2 4 and [Ni(CN) 4 ] 2 are paramagnetic 14. Which of the following is a complex compound? (a) KCl.MgCl 2.6H 2 O (b) K 2 SO 4.Al 2 (SO 4 ) 3.24H 2 O (c) [Co(ONO)(NH 3 ) 5 ]SO 4 (d) VO 2 Cl A flask contains 12 g of a gas of relative molecular mass 120 at a pressure of 100 atm. It was evacuated by meansof a pump until the pressure was 0.01 atm. Which of the following is the best estimate of the number of molecules left in the flask (N 0 = mole 1 ) (a) (b) (c) (d) A gas will approach ideal behaviour at (a) low temperature, low pressure (b) low temperature, high pressure (c) high temperature, low pressure (d) high temperature, high pressure 17. Milk is (a) fat dispersed in milk (b) fat dispersed in water (c) water dispersed in fat (d) water dispersed in oil 18. The calculated bond order in H 2 + ion is (a) 0 (b) ½ (c) -1/2 (d) 1

3 19. The formula of the compound is A 2 B 5. The number of electrons in the outermost orbits of A and B respectively are (a) 6 and 3 (b) 5 and 6 (c) 5 and 2 (d) 2 and Which of the following contains a co-ordinate covalent bond? (a) N 2 H 5 + (b) BaCl 2 (c) HCl (d) H 2 O 21. Which is paramagnetic and coloured (a) K 2 Cr 2 O 7 (b)(nh 4 ) 2 [TiCl 6 ] (c) VOSO 4 (d) K 3 [Cu (CN) 4 ] 22. C H bond distance is the longest in (a) C 2 H 2 (b) C 2 H 4 (c) C 2 H 6 (d) C 2 H 2 Br In presence of catalyst E a is lowered by 2kcal at 27 C. Hence rate will be (a) 20 times (b) 14 times (c) 28 times (d) 2 times 24. One mole of calcium phosphide on reaction with excess of water gives: (a) Two moles of phosphoric acid (b) One mole of phosphine (c) Two mole ofphosphine (d) One mole of phosphorus Pentoxide g of an oxide of a metal is converted to cholride completely and it yielded 5g of chloride. The equivalent weight of the metal is: (a) (b) (c) 12 (d) The half life time for the decomposition of a substance dissolved in CCl 4 is 2.5hours. at 30 C. The amount of the substance left after 10 hours, if the initial weight of substance is 160 gm, is (a) 5gm (b) 10gm (c) 15gm (d) 20gm 27. The solubility of AgI in NaI solution is less than that in pure water because, (a) AgI forms complex with NaI (b) of common ion effect (c) solubility product of AgI is less than that of NaI (d) the temperature of the solution decreases 28. The ph of a solution obtained by mixing 50 ml. of 0.4 M HCl with 50 ml of 0.2 NaOH is (a) log 2 (b) log (c) 1.0 (d) 2.0

4 29. poh of 10 8 M solution of NaOH will be (a) 8 (b) between 6 and 7 (c) between 7 and 8 (d) below Solubility of M 2 S salt is then find out solubility product. (a) (b) (c) (d) The solubility of Fe(OH) 3 is x mole L 1. Its Ksp would be (a) 9 x 3 (b) 3 x 4 (c) 27 x 4 (d) 9 x A weak acid HA has Ka= What would be the molar ratio of this acid and its salt with strong base so that ph of the buffer solution is 5? (a) 1 (b) 2 (c) 10 (d) 1/ The ph of a M NaOH solution is nearest to (a) 10 (b) 7 (c) 4 (d) Which of the following is used for preservation of grains? (a) Potassium permanganate (b) boric acid (c) sodium chloride (d) sodium benzoate 35. Tincture of iodine is (a) CHI 3 in alcohol (c) I 2 in KI (b) I 2 in alcohol (d) CHI 3 in KI 36. Which among the followings gases is used ti manufacture chloroform? (a) propane (b) ether (c) radone (d) methane 37. The specific rate constant of a first order reaction depends on the (a) concentration of the reactant (b) concentration of the product (c) time (d) temperature 38. In a reaction involving hydrolysis of an organic chloride RCl+ H 2 O ROH + HCl. (a) molecularity is 2, order of reaction is also 2 (b) molecularity is 2, order of reaction is1 (c) molecularity is 1, order of reaction is2 (d) molecularity is 1, order of reaction is also 1

5 39. The rate of reaction between A and B increases by a factor of 100, when the concentration of A is increased 10 folds, the order of reaction with respect to A is (a) 10 (b) 1 (c) 4 (d) The specific rate for a reaction is mole lit 1 min 1. The order of the reaction is (a) zero (b) one (c) two (d) three 41. The rate constant, the activation energy and Arhenius parameter of a chemical reaction at 25 C are s 1, kj mol 1 and s 1 respectively. The value of the rate constant at T is (a) s 1 (b) s 1 (c) inifintiy (d) s In a reaction 2A + B A 2 B, the reactant A will disappear at (a) half the rate at that B will decrease (b) the same rate at that B will decrease (c) the same rate at that A 2 B will form (d) twice the rate at that B will decrease 43. The rate constant k 1 of a reacti-onis found to be double that of rate constant k 2 of another reaction.the relationship between corresponding activation energies of the two reactions at same temperature (E 1 and E 2 ) can be represented as (a) E 1 > E 2 (b) E 1 < E 2 (c) E 1 = E 2 (d) None 44. In the reaction A + B Products, if B is taken in excess, then it is an example of (a) second order reaction (b) zero order reaction (c) pseudo-unimolecular reaction (d) first order reaction 45. Consider the following statement about entropy 1. The entropy is a measure of randomness. 2. Entropy is a function of the state of the system. 3. Entropy is an intensive property. 4. For a reversible cyclic process the integral of entropy will be zero. (a) 1, 2 and 3 are correct (b) 1, 2 and 4 are correct (c) only 4 is correct (d) 2 and 4 are correct 46. In acidic medium MnO 4 is an oxidising agent. MnO 4 + 8H + + 5e Mn 2+ If H + ions concentration is doubled, electrode potential of the half cell MnO 4, Mn 2+ Pt will (a) increase by mv (b) decrease by mv (c) increase by mv (d) decrease by mv

6 47. In which of the following cells will the emf be independent of the activity of the chloride ions (a) Zn ZnCl 2 (aq.) Pt (Cl 2 ) (b) Zn ZnCl 2 (aq.) KCl (aq.) Ag Cl(s), Ag (c) Ag, AgCl (s) KCl (aq.) Pt (Cl 2 ) (d) Hg, Hg 2 Cl 2 (s) KCl AgNO 3 (aq.) Ag 48. When lead storage battery discharges (a) SO 2 is evolved (b) PbSO 4 is consumed (c) lead is formed (d) sulphuric acid is consumed 49. Stronger the oxidising agent, greater is the (a) reduction potential (b) ionic behaviour (c) oxidation potential (d) none of these 50. The ionic conductivity of the cation and anion of the uni-univalent salt is 140 and 80 respectively. The molar conductivity of the salt is 160 W 1 cm 2 mole 1 (a) mercury cell (b) Daniel cell (c) lead storage cell (d) fuel cell

7 ANSWER KEYS 1. (a) 2. (b) 3. (c) 4. (b) 5. (b) 6. (a) 7. (c) 8. (b,c) 9. (a) 10. (d) 11. (d) 12. (c) 13. (b) 14. (c) 15. (b) 16. (c) 17. (b) 18. (b) 19. (b) 20. (a) 21. (c) 22. (c) 23. (c) 24. (c) 25. (a) 26. (b) 27. (b) 28. (c) 29. (b) 30. (b) 31. (c) 32. (c) 33. (b) 34. (d) 35. (a) 36. (d) 37. (d) 38. (b) 39. (d) 40. (a) 41. (b) 42. (b) 43. (d) 44. (c) 45. (b) 46. (a) 47. (c) 48. (d) 49. (a) 50. (d)

CHAPTER 7.0: IONIC EQUILIBRIA

Acids and Bases 1 CHAPTER 7.0: IONIC EQUILIBRIA 7.1: Acids and bases Learning outcomes: At the end of this lesson, students should be able to: Define acid and base according to Arrhenius, Bronsted- Lowry