MCQ ON SURFACE CHMISTRY & REDOX REACTION

In which of the following commercial processes a catalyst is not used [CPMT 1989] (a) Haber's process (b) Deacon's process (c) Solvay process (d) Lead chamber process A catalyst [IIT 1984; AFMC 1995; CBSE PMT 1995] (a) Increases the average kinetic energy of reacting molecules (b) Increases the activation energy (c) Alters the reaction mechanism (d) Increases the frequency of collisions of reacting species The coagulation of 100 ml of a colloidal sol of gold is completely prevented by addition of 0.25 g of a substance `X' to it before adding 10 ml of 1% solution. The gold number of `X' is (a) 0.25 (b) 25 (c) 250 (d) 2.5 Which one of the following is not a property of hydrophilic sols [AIIMS 1983, 84] (a) High concentrations of dispersed phase can be easily attained (b) Coagulation is reversible (c) Viscosity and surface tension are about the same as for water (d) The charge of the particle depends on the values of the medium; it may be positive, negative or even zero Peptising agent is (a) Always an electrolyte (b) Always a non-electrolyte (c) Electrolyte or non-electrolyte (d) A lyophilic colloid The catalyst used in the manufacture of methanol from water gas is [MP PET 2002] (a) (b) Ni + Mo (c) ZnO + (d) Pt + W Organic catalysts differ from inorganic catalysts [AFMC 1989] (a) By acting at very high temperature (b) By acting at low temperature (c) Being used up (d) Being proteinous in nature Commercial detergents mainly contain [CPMT 1993] (a) (b) (c) (d) In which of the following processes shape-selective catalysis is occurring [MP PET 1994] (a) Conversion of alcohol to gasoline (b) Synthesis of methanol from and (c) Polymerisation of ethylene (d) Synthesis of ammonia Which one of the following is used for reviving the exhausted permutite [EAMCET 2003] (a) HCl solution (b) solution (c) 10% solution (d) 10% NaCl solution The ability of a catalyst to accelerate the chemical reaction is known as [CPMT 2000; KCET 2000] (a) Selectivelty (b) Activity (c) Negative catalyst (d) None of these , in reactions, acts as [MADT Bihar 1983] (a) Oxidizing agent (b) Reducing agent (c) Acid catalyst (d) None of these On addition of one ml of 10% NaCl solution to 10 ml gold sol in the presence of 0.25 gm of starch. The coagulation is just prevented, starch has gold number [MP PET 2004] (a) 0.025 (b) 0.25 (c) 2.5 (d) None Milk is an example of [MP PET 2001; JIPMER 2002; MP PMT 2002,04] (a) Pure solution (b) Gel (c) Emulsion (d) Suspension When a piece of wire of copper is dipped in solution, the colour of the solution turns blue due to [MP PMT 1992; JIPMER 2002] (a) Formation of soluble complex (b) Oxidation of copper (c) Oxidation of silver (d) Reduction of copper and can reduce can reduce and can reduce [IIT 1981] (a) (b) (c) (d) None of the above Consider the following statements : In the chemical reaction (1) Manganese ion is oxidised (2) Manganese ion is reduced (3) Chloride ion is oxidised (4) Chloride ion is reduced Which of these statements are correct [NDA 1999] (a) 1 and 3 (b) 1 and 4 (c) 2 and 3 (d) 2 and 4 The oxide which cannot act as a reducing agent is [CBSE PMT 1995; AIIMS 2000; JIPMER 2002; Kurukshetra CEE 2002] (a) (b) (c) (d) In the reaction between ozone and hydrogen peroxide, acts as [RPET 2000] (a) Oxidising agent (b) Reducing agent (c) Bleaching agent (d) Both oxidising and bleaching agent The oxidation state of each oxygen atom in is [NCERT 1971] (a) – 2 each (b) – 2 and zero (c) – 1 each (d) None of the above The oxidation state of sulphur in is [Bihar MEE 1996] (a) 4 (b) 2 (c) 6 (d) – 6 The charge on cobalt in is [CPMT 1985, 93] (a) – 6 (b) – 3 (c) + 3 (d) + 6 Oxidation number of in is [CPMT 1989] (a) – 2 (b) + 2 (c) – 6 (d) + 6 A metal ion after loss of three electrons in a reaction will have an oxidation number equal to [CPMT 1980, 83, 84, 94, 99] (a) Zero (b) + 2 (c) + 3 (d) + 6 Oxidation number of oxygen in ozone is [MP PET 2000; MP PMT 2001] (a) + 3 (b) – 3 (c) – 2 (d) 0 The oxidation states of sulphur in the anions and follow the order [CBSE PMT 2003] (a) (b) (c) (d) The oxidation number of hydrogen in is (a) + 1 (b) – 1 (c) 2 (d) 0 Which of the following is not a redox reaction [RPMT 1999] (a) (b) (c) (d) Which of the following equations is a balanced one [EAMCET 1980] (a) (b) (c) (d) In the equation Identify the metal [AFMC 1998] (a) Copper (b) Iron (c) Gold (d) Zinc In alkaline condition reacts as . The equivalent weight of would be (Atomic mass of = 39, Mn = 55, O = 16) [MP PMT 2002] (a) 158.0 (b) 79.0 (c) 52.7 (d) 31.6 In acidic medium, equivalent weight of is [AFMC 1988] (a) (b) (c) (d) ANS. 1. (c) In Haber's process we use iron as a catalyst, In Deacon's process we use as a catalyst and in lead chamber process we use as a catalyst but in solvay process no catalyst is used. 2. (d) A catalyst can increase the rate or reaction and hence increases the frequency of collision of reacting species. 3. (b) 250 mg of X is present in 100 ml of colloidal sol of gold. By definition, gold no. of X is that amount of it in mg which is present in 10 ml of colloidal gold solution. Hence in 10 ml, the amount of X present is 25 mg which is the gold number of X. 4. (c) Viscosity and surface tension are not same for water in hydrophillic sols. 5. (a) Process of converting precipitate into colloidal particles by adding suitable electrolyte called peptisation and stabilizing agent (electrolytes) as peptizing agent. 6. (c) 7. (d) Organic catalyst are proteinous in nature and obtain from living cell. 8. (a) Commercial detergents mainly contain salts of higher fatty acids. 9. (a,c) Shape selective catalyst are zeolites and zeolites are alminosilicates of general formula . Zeolites are used in conversion of alcohol to gasoline and in polymerisation of ethylene. 10. (d) 10% solution is used for reviving the exhaust permutite. 11. (b) The ability of a catalyst to accelerate the chemical reaction is known as its activity. Degree of acceleration can be as high as times in certain reactions. 12. (c) may be written as and all the tri-positive ions are Lewis acid hence it can be acts as acid catalyst. 13. (d) 14. (c) Milk is the example of emulsion of fat globules in water. 15. (b) ;. 16. (d) can be oxidised to only by electrolysis. 17. (c) Because the oxidation state of chlorine is – 4 to 0 while Manganese ion is reduced because its oxidation state + 4 to + 2. 18. (c) is a acidic oxide. 19. (b) acts as a reducing agent in the reaction between and . 20. (c) In oxygen show – 1 oxidation state. 21. (c) . 22. (c) In complex Co shows + 3 oxidation state. 23. (d) . 24. (d) . Thus the oxidation number of metal = + 6. 25. (d) Molecule and free atoms show zero oxidation state is a molecule shows zero oxidation state. 26. (b) Oxi. state of sulphur in Oxi. state of sulphur in Oxi state of sulphur in . 27. (b) . 28. (d) In the reaction , change in oxidation state is not taking place. 29. (b) is the balanced reaction. 30. (c) . 31. (a) (. 32. (c) . SURFACE CHEMISTRY & REDOX REACTION 3 *** Mrs Shallu Aggarwal Mobile #. 98786-08983 ***