Title REDOX REACTIONS Q-9.pdf ✅

CLASS : XIIth SUBJECT : CHEMISTRY DATE : DPP NO. : 9 1. Addition of zinc powder to CuSO4 solution precipitates copper due to : a) Reduction of Cu2+ b)Reduction of SO2― 4 c) Reduction of Zn d)Hydrolysis of CuSO4 2. Titrations in which liberated I2 is estimated to carry out the volumetric estimations are known as ....titrations. a)Iodometric b)Iodimetric c) Acidimetric d)Alkalimetric 3. In the course of chemical reaction, an oxidant : a) Loses electron b)Gains electron c) Either of these d)None of these 4. In alkaline condition KMnO4 reacts as follows : 2KMnO4 +2KOH ⟶2K2MnO4 + H2O + O. The eq. wt. of KMnO4 is : a) 52.7 b)158 c) 31.6 d)79 5. Oxidation number of nitrogen in AgNO3 is: a) +5 b) ―3 c) +3 d) ―2 6. Total number of AlF3 molecules in a sample of AlF3 containing 3.01 × 1023 ions of F ― is : a) 9 × 1024 b)3 × 1024 c) 7 × 1023 d)1023 7. Oxidation number of N in NOCl is : a) +3 b)+2 c) +1 d)+4 8. The oxidation state of chlorine is highest in the compound : a) Cl2 b)HCl c) Cl2O d)Cl2O7 9. How many gram of KMnO4 are contained in 4 litre of 0.05 N solution? The KMnO4 is to be used as an oxidant in acidic medium : a) 1.58 g b)15.8 g c) 6.32 g d)31.6 g 10. The reaction; H2S + H2O2 ⟶2H2O + S shows : a) Acidic nature of H2O2 b)Alkaline nature of H2O2 c) Oxidising action of H2O2 d)Reducing action of H2O2 Topic :-REDOX REACTIONS
11. For redox reaction, MnO― 4 + C2O 2― 4 + H +⟶Mn2+ + CO2 + H2O coefficient of reactants in balanced states are MnO― 4 C2O 2― 4 H + a) 2 5 16 b)16 5 2 c) 5 16 2 d)2 16 5 12. Chlorine has +1 oxidation state in : a)HCl b)HClO3 c) Cl2O d)ICl3 13. Which statement is incorrect? a) Oxidation of a substance is followed by reduction of another b)Reduction of a substance is followed by oxidation of another c) Oxidation and reduction are complementary reactions d)It is not necessary that both oxidation and reduction should take place in the same reaction 14. In the standardization of Na2S2O3 using K2Cr2O7 by iodometry, the equivalent weight of K2Cr2 O7 is : a) (molecular weight)/2 b) (molecular weight)/6 c) (molecular weight)/3 d) Same as molecular weight 15. When SO2 is passed in a solution of potassium iodate, the oxidation state of iodine changes from : a) +5 to 0 b)+5 to −1 c) −5 to 0 d)−7 to −1 16. The halogen that shows same oxidation state in all its compounds with other elements is: a)I2 b)F2 c) Cl2 d)Br2 117. The reaction, P4 + 3NaOH + 3H2O⟶3NaH2PO2 + PH3 is an example of a) Disproportionation reaction b)Neutralisation reaction c) Double-decomposition reaction d)Pyrolytic reaction 18. Titrations in which I2 solution is used as intermediate are known as ....titrations. a)Iodometric b)Iodimetric c) Acidimetric d)alkalimetric 19. In the reaction,Cr2O 2― 7 +14H + +6I ― ⟶2Cr 3+ +7H2O + 3I2, which element is reduced? a) I b)O c) H d)Cr 20. Carbon reacts with oxygen to form two oxides, CO and CO2. This is because : a) Carbon has two crystalline forms b)Carbon has two oxidation states
c) Oxygen donates as well as accept electrons d)Oxygen has a strong affinity for carbon