Which metal from the following list will NOT displace hydrogen from dilute hydrochloric acid?
Answer
Copper
The correct answer is Copper — Select the option that corresponds to copper.
Step-by-step solution
- Recall the reactivity series: K, Ca, Na, Mg, Al, Zn, Fe, Ni, Sn, Pb, (H), Cu, Ag, Au.
- A metal will displace hydrogen from dilute only if it is placed above hydrogen in the series.
- Check each option: Magnesium, Zinc, and Iron are all above hydrogen, so they can release gas.
- Copper lies below hydrogen, therefore it does not react with dilute .
- Select the option that corresponds to copper.
Common mistake: Choosing iron, forgetting that iron is above hydrogen in the reactivity series and does react (though slowly).
Concept tested: Reactivity series of metals
Published · How this solution was prepared and checked
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