A 3 and 6 B 6 and 3 C 6 and 12 D 12 and 6. 6. In of the following reactions is a positive ion reduced? A Iodide iodine  B Nickel(II) nickel(III)  C Cobalt(III) cobalt(II)  D Sulphate sulphite  7. In which reaction is hydrogen gas acting as an oxidising agent? A H2 + CuO H2O + Cu → B H2 + C2H4 C2H6 → C H2 + Cl2 2HCl → D H2 + 2Na 2NaH → 8. Iodide ions can be oxidised acidified potassium permanganate solution. The equations are: How many moles of iodide ions are oxidized by one mole of permanganate ions? A 1.0 B 2.0 C 2.5 D 5.0 9. During a redox process in acid solution, iodate ions are converted into iodine. + – – 2IO3 + 12H + xe I2(aq) + 6H2O(l) → (aq) (aq) To balance the equation, what is the value of x? A 2 B 6 C 10 D 12 10. The following reactions take place when nitric acid is added to zinc. How many moles of NO3– are reduced by one mole of zinc? (aq)
A 3 and 6 B 6 and 3 C 6 and 12 D 12 and 6. 6. In of the following reactions is a positive ion reduced? A Iodide  iodine B Nickel(II)  nickel(III) C Cobalt(III)  cobalt(II) D Sulphate  sulphite 7. In which reaction is hydrogen gas acting as an oxidising agent? A H2 + CuO → H2O + Cu B H2 + C2H4 → C2H6 C H2 + Cl2 → 2HCl D H2 + 2Na → 2NaH 8. Iodide ions can be oxidised acidified potassium permanganate solution. The equations are: How many moles of iodide ions are oxidized by one mole of permanganate ions? A 1.0 B 2.0 C 2.5 D 5.0 9. During a redox process in acid solution, iodate ions are converted into iodine. – + – 2IO3 (aq) + 12H (aq) + xe → I2(aq) + 6H2O(l) To balance the equation, what is the value of x? A 2 B 6 C 10 D 12 10. The following reactions take place when nitric acid is added to zinc. How many moles of NO3– (aq) are reduced by one mole of zinc?