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MODEL PAPER - 1 [2026] — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceMODEL PAPER - 1 [2026]3 Marks
Question
A zinc plate was kept in a glass container having copper sulphate solution. On examining it was found that the blue colour of the solution is fading slowly. After a few days when the zinc plate was taken out of the solution, a number of small holes were noticed in it. State the reason and give chemical equation of the reaction involved.
✓

Answer

Zinc is more reactive than copper. Hence, when a zinc plate is kept in a solution of copper sulphate, it slowly displaces copper from the solution and blue colour of the solution keeps fading away. Because of zinc going into solution as zinc sulphate, a number of holes are seen in the zinc plate. The reaction is$
\underset{\text { Blue }}{\mathrm{CuSO}_{4}(a q)}+\mathrm{Zn}(s) \rightarrow \underset{\text { Colourless }}{\mathrm{ZnSO}_{4}(a q)}+\mathrm{Cu}(s)
$

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