Topic9 graded practice

IB SL Chem Topic 9: Redox Reactions Graded Practice 6. What is the order of decreasing reactivity of the metals (most reactive first)? Zn(s) + Sn 2+ (aq) → Zn 2+ (aq) + Sn(s) Cu(s) + Zn 2+ (aq) → No Reaction Sn(s) + Cu 2+ (aq) → Sn 2+ (aq) + Cu(s) Ag(s) + Cu 2+ (aq) → No Reaction A. Zn > Cu > Sn > Ag B. Sn > Zn > Ag > Cu C. Ag > Cu > Zn > Sn D. Zn > Sn > Cu > Ag 7. What is the oxidation half-equation in the redox reaction? 2S 2 O 3 2– (aq) + I 2 (aq) → S 4 O 6 2– (aq) + 2I – (aq) A. I 2 (aq) + 2e – → 2I – (aq) B. 2I – (aq) → I 2 (aq) + 2e – C. 2S 2 O 3 2– (aq) → S 4 O 6 2– (aq) + 2e – D. S 4 O 6 2– (aq) + 2e – → 2S 2 O 3 2– (aq) 8. Which statements are correct for a voltaic cell? I.A spontaneous redox chemical reaction produces electrical energy. II. Oxidation occurs at the cathode (negative electrode). III. Electrons flow from anode (negative electrode) to cathode (positive electrode). A. I and II only B. I and III only C. II and III only D. I, II and III 9. Which change represents oxidation? A. HClO 4 to HClO 3 B. N 2 to NH 3 C. N 2 O to NO D. SO 4 2− to SO 3 2− 10. Which element is reduced in the following decomposition? (NH 4 ) 2 Cr 2 O 7 (s) → N 2 (g) + Cr 2 O 3 (s) + 4H 2 O(g) A. N B. H C. Cr D. O 11. Which of the following is not a redox reaction? A. CH 4 (g) + Cl 2 (g) → CH 3 Cl(g) + HCl(g) B. C(s) + O 2 (g) → CO 2 (g) C. 2CO(g) → CO 2 (g) + C(s) D. CH 3 COOH(aq) + NaOH(aq) → CH 3 COONa(aq) + H 2 O(l) 12. What occurs at the anode (positive electrode) during the electrolysis of molten strontium bromide? A. Formation of bromine and oxidation B. Formation of bromine and reduction C. Formation of strontium and oxidation D. Formation of strontium and reduction 13. Consider the following half-equations: I 2 (s) + 2e – ⇌ 2I – (aq) (brown) (colorless) MnO 4 – (aq) + 8H + (aq) + 5e – ⇌ Mn 2+ (aq) + 4H 2 O (l) (purple) (colorless) Which statement is correct for the reaction between KMnO 4 (aq) and KI (aq) in acidic conditions? A. MnO 4 – reduces I – to I 2 . B. I – reduces MnO 4 – to Mn 2+ . C. The colour changes from brown to purple. D. MnO 4 – is oxidized to Mn 2+ . 2 | P a g e