CIE iGCSE Co-Ordinated Science C9.4 Reactivity series Exam Style Questions Paper 2
▶️ Answer/Explanation
Lithium reacts vigorously with cold water, producing hydrogen gas and floating on the surface. Magnesium reacts only with steam, zinc reacts very slowly with steam, and iodine does not react with water to produce hydrogen.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
Magnesium reacts rapidly with steam but only very slowly with cold water. Calcium reacts readily with cold water (not just slowly), sodium reacts very vigorously with cold water (often violently), and copper does not react with either cold water or steam (it is below hydrogen in the reactivity series). Therefore, magnesium (option C) is the only metal that matches the given description.
✅ Answer: (C)
✅ Answer: (C)
▶️ Answer/Explanation
Copper is more reactive than silver, since silver oxide is reduced more easily than copper oxide, so copper displaces silver from solution.
Copper atoms lose electrons to form blue \(\text{Cu}^{2+}\) ions in solution, so the colourless solution slowly turns blue and the copper strip slowly dissolves.
Silver ions gain electrons, depositing as silver-grey solid silver metal on the copper strip.
✅ Answer: (B)
Copper atoms lose electrons to form blue \(\text{Cu}^{2+}\) ions in solution, so the colourless solution slowly turns blue and the copper strip slowly dissolves.
Silver ions gain electrons, depositing as silver-grey solid silver metal on the copper strip.
✅ Answer: (B)
▶️ Answer/Explanation
Statement 1 shows W is more reactive than X (W reduces X’s oxide).
Statement 2 shows Z is less reactive than W, but more reactive than X and Y.
Statement 3 shows X is more reactive than Y, giving the overall order W > Z > X > Y.
✅ Answer: (B)
Statement 2 shows Z is less reactive than W, but more reactive than X and Y.
Statement 3 shows X is more reactive than Y, giving the overall order W > Z > X > Y.
✅ Answer: (B)
▶️ Answer/Explanation
Zinc is more reactive than copper, so it displaces copper from aqueous copper sulfate: \(\text{Zn} + \text{CuSO}_4 \rightarrow \text{ZnSO}_4 + \text{Cu}\).
As colourless zinc sulfate replaces the blue copper sulfate solution, the blue colour fades to colourless, and reddish-brown copper metal is deposited.
Copper is less reactive than aluminium so cannot displace it (A is wrong), magnesium is more reactive than iron so magnesium oxide would not be reduced by iron (B is wrong), and copper is less reactive than potassium so cannot displace it from potassium oxide (C is wrong).
✅ Answer: (D)
As colourless zinc sulfate replaces the blue copper sulfate solution, the blue colour fades to colourless, and reddish-brown copper metal is deposited.
Copper is less reactive than aluminium so cannot displace it (A is wrong), magnesium is more reactive than iron so magnesium oxide would not be reduced by iron (B is wrong), and copper is less reactive than potassium so cannot displace it from potassium oxide (C is wrong).
✅ Answer: (D)