Tiêu đề REDOX REACTIONS Q-6.pdf ✅

CLASS : XIIth SUBJECT : CHEMISTRY DATE : DPP NO. : 6 1. Which compound has oxidation number of carbon equal to zero? a) C6H6 b)CH3 c) C2H4 d)C6H12O6 2. In the reaction, 2KMnO4 +16HCl ⟶2KCl + 2MnCl2 +8H2O + 5Cl2, the reduction product is : a) Cl2 b)MnCl2 c) KCl d)H2O 3. The oxidation number of phosphorus in Mg2P2O7 is : a) + 5 b) ― 5 c) +6 d) ― 7 4. 1 mole of chlorine combines with a certain weight of a metal giving 111 g of its chloride. The atomic weight of the metal (assuming its valency to be 2) is : a) 40 b)20 c) 80 d)None of these 5. Oxidation state of chromium a) +10 b)+6 c) +3 d)+2 6. Oxidation states of the metal in the minerals haematite and magnetite, respectively, are a)II, III in haematite and III in magnetite b)II, III in haematite and II in magnetite c) II in haematite and II, III in magnetite d)III in haematite and II, III in magnetite 7. The colour of K2Cr2O7 changes from red-orange to lemon-yellow on treatment with KOH(aq) because of : a) Reduction of Cr(VI) to Cr(III) b)Formation of chromium hydroxide c) Conversion of dichromate into chromate ion d)Oxidation of potassium hydroxide to potassium peroxide 8. How many electrons are involved in oxidation of KMnO4 in basic medium? a) 1 b)2 c) 5 d)3 Cr O O O O O Topic :-REDOX REACTIONS
9. The oxidation state of nitrogen in NH4NO3 is : a) −3 and +5 b)+3 and +5 c) +5 d)+3 10. When Sn(IV) chloride is treated with excess HCl, the complex [SnCl6 ] 2― is formed. The oxidation state of Sn in this complex is: a) +6 b)−2 c) +4 d)−5 11. Oxidation number of chlorine in HOCl is : a) Zero b)−1 c) +1 d)+2 12. In the reaction, C + 4HNO3 ⟶CO2 +2H2O + 4NO2, HNO3 acts as : a) An oxidising agent b)An acid c) An acid as well as oxidising agent d)A reducing agent 13. Change of hydrogen into proton is : a) Oxidation of hydrogen b)Acid-base reaction c) Reduction of hydrogen d)Displacement reaction 14. 8 g of sulphur are burnt to form SO2 which is oxidised by Cl2 water. The solution is treated with BaCl2 solution. The amount of BaSO4 precipitated is : a) 1.0 mole b)0.5 mole c) 0.24 mole d)0.25 mole 15. The number of mole of ferrous oxalate oxidised by one mole of KMnO4 is: a) 1/5 b)3/5 c) 2/3 d)5/3 16. Reactants react in the equal number of ........ to give products. a) Mole b)Weights c) Equivalent d)All of these 17. Mole and millimole of reactants react in the ..........as represented by balanced stoichiometric equation. a) Molar ratio b)Equal amount c) Both (a) and (b) d)None of these 18. The reaction of white phosphorus with aqueous NaOH gives phosphine along with another phosphorus containing compound. The reaction type the oxidation states of phosphorus in phosphine and the other product are respectively : a) Redox reaction; −3 and −5 b)Redox reaction; +3 and +5 c) Disproportionation reaction; −3 and +1 d)Disproportionation reaction; −3 and +3