Experiment: Iron nails were placed in a solution of copper sulfate, and after 30 minutes, they were rinsed and weighed.Observation: Mass increased due to a layer of another metal.Question: What does this confirm?
Correct answer: A. Displacement reaction where iron replaces copper.
- A. Displacement reaction where iron replaces copper.
- B. Corrosion by copper ions.
- C. Coating due to evaporation.
- D. Precipitation of salt on iron.
Explanation
The correct answer is Option A: Displacement reaction where iron replaces copper. The increase in mass of the iron nails confirms the formation of a layer of another metal, which occurs as a result of a displacement reaction where iron replaces copper in the copper sulfate solution. The other options are incorrect because they do not explain the observed increase in mass due to the formation of a different metal layer.
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About Scientific Reasoning
Scientific reasoning evaluates hypotheses through observations, variables, controls, measurements and experimental results. Questions involve identifying independent and dependent variables, recognising a fair test, interpreting tables or graphs, distinguishing evidence from opinion, and deciding whether data supports, rejects or leaves a hypothesis unresolved.
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