The apparatus heats a metal in a stream of steam; any hydrogen produced is collected and burned at the tube end. Cleaned zinc glows and hydrogen burns; clea...
Question 1 Report
The apparatus heats a metal in a stream of steam; any hydrogen produced is collected and burned at the tube end. Cleaned zinc glows and hydrogen burns; cleaned copper shows no reaction. What does this comparison show?
Answer Details
The steam test separates metals in the middle of the reactivity series. A metal that reacts with steam is reactive enough to strip oxygen from water and release hydrogen; one that does not is below that threshold.
Cleaned zinc glows and gives hydrogen that burns at the tube end: \( \text{Zn} + \text{H}_2\text{O} \rightarrow \text{ZnO} + \text{H}_2 \). Copper under identical conditions shows nothing, because copper cannot reduce water at all. The only valid conclusion is that zinc is more reactive than copper.
Note the fair test built into the apparatus: same steam supply, same heating, both surfaces cleaned of oxide. Because conditions are identical, the difference must come from the metals themselves, not from the setup.
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