Title Chemistry ÔÇó Final Step-A ÔÇó VMC.pdf ✅

Vidyamandir Classes VMC | Final Step - A 1 Class XI | Chemistry Final Step - A | Chemistry Stoichiometry & Redox Reaction CHOOSE THE CORRECT ALTERNATIVE. ONLY ONE CHOICE IS CORRECT. HOWEVER, QUESTIONS MARKED ‘*’ MAY HAVE MORE THAN ONE CORRECT OPTION. 1. In which of the following reactions H2O2 acts as a reducing agent? 1. H O 2e 2H 2H O 2 2 2      2. H O 2e O 2H 2 2 2      3. H O 2e 2OH 2 2     4. H O 2OH 2e O 2H O 2 2 2 2       (A) 1, 2 (B) 3, 4 (C) 1, 3 (D) 2, 4 2. What product are expected from the disproportionation reaction of hypochlorous acid ? (A) HClO3 & Cl2O (B) HClO2 & HClO4 (C) HCl & Cl2O (D) HCl & HClO3 3. Which of the following chemical reactions depicts the oxidizing behaviour of H2SO4 ? (A) 2 4 2 2 2 2HI H SO I SO 2H O     (B) Ca(OH) H SO CaSO 2H O 2 2 4 4 2    (C) NaCl H SO NaHSO HCl    2 4 4 (D) 5 2 4 2PCl H SO   3 2 2 2POCl 2HCl SO Cl   4. The oxidation state of Cr in 3 4 2 [Cr(NH ) Cl ] is : (A) 0 (B) +1 (C) +2 (D) +3 5. MnO4  is a good oxidizing agent in different medium changing to : 2 2 MnO Mn ; MnO MnO 4 4 4       ; MnO MnO ; MnO Mn O 4 2 4 2 3     Changes in oxidation number respectively, are : (A) 1, 3, 4, 5 (B) 5, 4, 3, 2 (C) 5, 1, 3, 4 (D) 2, 6, 4, 3 6. Which of the following reaction is possible at anode ? (A) F 2e 2F 2     (B) 2 2 1 2H O 2e H O 2      (C) 3 2 2Cr 7H O Cr O 14H 6e 2 2 7         (D) None of the above 7. A measured temperature on Fahrenheit scale is 200 °F. What will this reading be on Celsius scale ? (A) 40°C (B) 94°C (C) 93.3°C (D) 30°C 8. The number of atoms present in one mole of an element is equal to Avogadro number. Which of the following element contains the greatest number of atoms ? (A) 4g He (B) 46g Na (C) 0.40g Ca (D) 12g He 9. One mole of any substance contains 23 6.022 10  atoms/molecules. Number of molecules of H SO 2 4 present in 100 mL of 0.02 M H SO 2 4 solution is _____ . (A) 20 12.044 10  molecules (B) 23 6.022 10  molecules (C) 23 1 10  molecules (D) 23 12.044 10  molecules
Vidyamandir Classes VMC | Final Step - A 2 Class XI | Chemistry 10. If the density of a solution is 1 3.12g mL , the mass of 1.5 mL solution in significant figure is ______ . (A) 4.7g (B) 3 4680 10 g   (C) 4.680g (D) 46.80g 11. Which of the following statements about a compounds is incorrect ? (A) A molecule of a compound has atoms of different elements (B) A compound cannot be separates into its constituent elements by physical methods of separation (C) A compound retains the physical properties of its constitution elements (D) The ratio of atoms of different elements in a compound is fixed 12. Which of the following statements indicates that law of multiple proportion is being followed. (A) Sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio1: 2 (B) Carbon forms two oxides namely CO2 and CO, where masses of oxygen which combine with fixed mass of carbon are in the simple ratio 2:1 (C) When magnesium burns in oxygen, the amount of magnesium taken for the reaction is equal to the amount of magnesium in magnesium oxide formed (D) At constant temperature and pressure 200mL of hydrogen will combine with 100 mL oxygen to produce 200 mL of water vapour *13. One mole of oxygen gas at STP is equal to ______ . (A) 23 6.022 10  molecules of oxygen (B) 23 6.022 10  atoms of oxygen (C) 16g of oxygen (D) 32g of oxygen *14. Which of the following solutions have the same concentration ? (A) 20 g of NaOH in 200 mL of solution (B) 0.5 mol of KCl in 200 mL of solution (C) 40 g of NaOH in 100 mL of solution (D) 20 g of KOH in 200 mL of solution *15. Which of the following terms are unitless ? (A) Molality (B) Molarity (C) Mole fraction (D) Mole percent *16. One of the statements of Dalton’s atomic theory is given below: “Compounds are formed when atoms of different elements combine in a fixed ratio”. Which of the following laws is not related to this statement ? (A) Law of conservation of mass (B) Law of definite proportions (C) Law of multiple proportions (D) Avogadro law 17. Thiosulphate reacts differently with iodine and bromine in the reactions given below : 2 2 2 3 2 4 6 2S O I S O 2I       2 2 S O Br 5H O 2SO 2Br 10H 2 3 2 2 4          Which of the following statements justifies the above dual behaviour of thiosulphate ? (A) Bromine is a stronger oxidant than iodine (B) Bromine is a weaker oxidant than iodine (C) Thiosulphate undergoes oxidation by bromine and reduction by iodine in the reactions. (D) Bromine undergoes oxidation and iodine undergoes reduction in these reactions. 18. The oxidation number of an element in a compound is evaluated on the basis of certain rules. Which of the following rules is not correct in this respect ? (A) The oxidation number of hydrogen is always 1 (B) The algebraic sum of all the oxidation numbers in a compound is zero (C) An element in the free or the uncombined state bears oxidation number zero (D) In all its compounds, the oxidation number of fluorine is 1 19. In which of the following compounds, an element exhibits two different oxidation states. (A) NH OH 2 (B) NH NO 4 3 (C) N H2 4 (D) N H3 20. The largest oxidation number exhibited by an element depends on its outer electronic configuration. With which of the following outer electronic configurations the element will exhibit largest oxidation number ? (A) 1 2 3d 4s (B) 3 2 3d 4s (C) 5 1 3d 4s (D) 5 2 3d 4s
Vidyamandir Classes VMC | Final Step - A 3 Class XI | Chemistry 21. Identify disproportionation reaction : (A) CH 2O CO 2H O 4 2 2 2    (B) CH 4Cl CCl 4HCl 4 2 4    (C) 2 2 2 2F 2OH 2F OF H O       (D) 2 2 3 2 2NO 2OH NO NO H O        *22. Which of the following statement(s) is(are) not true about the following decomposition reaction? 3 2 2KClO 2KCl 3O   (A) Potassium is undergoing oxidation (B) Chlorine is undergoing oxidation (C) Oxygen is reduced (D) None of the species are undergoing oxidation or reduction *23. Identify the correct statement (s) in relation to the following reaction : Zn 2HCl ZnCl H   2 2 (A) Zinc is acting as an oxidant (B) Chlorine is acting as a reductant (C) Hydrogen ion is acting as an oxidant (D) Zinc is acting as a reductant *24. The exhibition of various oxidation states by an element is also related to the outer orbital electronic configuration of its atoms. Atom(s) having which of the following outermost electronic configurations will exhibit more than one oxidation state in its compounds. (A) 1 3s (B) 1 2 3d 4S (C) 2 2 3d 4s (D) 2 3 3s 3p Reasoning Type Questions for 25 - 26 (A) Both A and R are true and R is the correct explanation of A (B) Both A and R are true but R is not the correct explanation of A (C) A is true but R is false (D) Both A and R are false 25. Assertion (A) : Among halogens F2 is the best oxidant. Reason (R) : F is the most electronegative atom. 26. Assertion (A) : In the reaction between potassium permanganate and potassium iodide, permanganate ions act as oxidising agent. Reason (R) : Oxidation state of manganese changes from   2 to 7 during the reaction. 27. A gaseous hydrocarbon give upon combustion, 0.72 g of water and 3.08 g of CO2. The empirical formula of the hydrocarbon is : (A) C2H4 (B) C3H4 (C) C6H5 (D) C7H8 28. The density of a solution prepared by dissolving 120 g of urea (mol. mass = 60 u) in 1000 g of water is 1.15 g/mL. The molarity of this solution is : (A) 0.50 M (B) 1.78 M (C) 1.02 M (D) 2.05 M 29. The mass of potassium dichromate crystals required to oxidise 750 cm3 of 0.6 M Mohr’s salt solution is: (Molar mass = 392) (A) 0.49 g (B) 0.45 g (C) 22.05 g (D) 2.2 g 30. Amount of oxalic acid present in a solution can be determined by its titration with KMnO4 solution in the presence of H2SO4. The titration gives unsatisfactory result when carried out in the presence of result when carried out in the presence of HCl because HCl : (A) Gets oxidised by oxalic acid to chlorine (B) Furnishes H+ ions in addition to those form oxalic acid (C) Reduces permanganate to 2 Mn  (D) Oxidises oxalic acid to carbon dioxide and water 31. In the reaction : 3 2 2Al(s) 6HCl(aq) 2Al (aq) 6Cl (aq) 3H (g)       (A) 6L HCl(aq) is consumed for every 3L H2(g) produced (B) 33.6 L H2(g) is produced T and P for every mole Al that reacts (C) 67.2 L H2 (g) at STP is produced for every mole Al that reacts (D) 11.2 L H2(g) at STP is produced for every mole HCl(aq) consumed
Vidyamandir Classes VMC | Final Step - A 4 Class XI | Chemistry 32. If we consider that 1/6, in place 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will : (A) Be a function of the molecular mass of the substance (B) Remain unchanged (C) Increase two fold (D) Decrease twice 33. What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass 10.8) from the reduction of boron trichloride by hydrogen? (A) 89.6 L (B) 67.2 L (C) 44.8 L (D) 22.4 L 34. In an organic compound of molar mass 108 g 1 mol C, Hand N atoms are present in 9 :1: 3.5 by weight. Molecular formula can be : (A) C6H8N2 (B) C7H10N (C) C5H6N3 (D) C4H18N3 35. In the reaction : 2 4 2 4 2 2 2Ag 2H SO Ag SO 2H O SO     . Sulphuric acid acts as : (A) an oxidizing agent (B) a reducing agent (C) a catalyst (D) an acid as well as an oxidant 36. What is the equivalent weight of FeSO4 in the following reaction? FeSO Fe (SO ) 4 2 4 3  (A) M/2 (B) 2M (C) M (D) M/4 (M = molecular weight of FeSO4) 37. Oxidation state of sulphur atoms in 2 S O4 6  from left to right respectively are : O O || || O S S S S O || || O O Θ      Θ (A) + 6, 0, 0, +6 (B) +3, +1, + 1, + 3 (C) +5, 0, 0, +5 (D) +4, +1, +1 , +4 38. Select the correct statement in the following reaction : NH NO N 2H O 4 2 2 2   (A) Oxidation number of N has changed from – 2 to +2 (B) Oxidation number of N in NH4  changed from –3 to 0 and that in NO2  changed from + 3 to 0 (C) Oxidation number of N in NH4  changed from + 1 to 0 and that in NO2  changed from – to 0 (D) No change 39. 1 mole of FeC2O4 is oxidized by x moles of 2 Cr O2 7  in acidic medium, x is : (A) 3 (B) 1.5 (C) 0.5 (D) 1.0 *40. 0.1 mole of NaHC2O4 is : (A) Neutralized by 0.1 mole of NaOH (B) Neutralized by 0.05 mole of Ca(OH)2 (C) Oxidized by 0.04 mole of KMnO4/H+ (D) Oxidized by 0.02 mole of K2MnO4/OH– 41. What is the mass of the precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8 % NaCl solution ? (Ag = 107.8, N = 14, O = 16, Na = 23, Cl = 35.5) (A) 3.5 g (B) 7 g (C) 14 g (D) 28 g 42. If avogardo number NA, is changed from 23 1 20 1 6.022 10 mol to 6.022 10 mol     , this would change : (A) the mass of one mole of carbon (B) the ratio of chemical species to each other in a balanced equation (C) the ratio of elements to each other in a compound (D) the definition of mass in units of grams 43. Equal masses of H2, O2 and methane have been taken in a container of volume V at temperature 27 C in identical conditions. The ratio of the volumes of gases H2 : O2 : methane would be : (A) 8 : 16 : 1 (B) 16 : 8 : 1 (C) 16 : 1 : 2 (D) 8 : 1 : 2