When a piece of copper wire is immersed with solution of AgNO3, the colour of solution becomes blue. It is due to

Correct answer: B. Reduction of Cu

  • A. Oxidation of Cu
  • B. Reduction of Cu
  • C. Oxidation of Ag
  • D. Formation of Ag-Cu alloy

Explanation

When a copper wire is dipped in a silver nitrate (AgNO3) solution, a displacement reaction occurs. This means that the more reactive copper (Cu) displaces the less reactive silver (Ag) from the solution. Here's the breakdown:Oxidation: Copper atoms lose electrons and become positively charged copper ions (Cu²⁺). This is the oxidation half-reaction:Cu(s) → Cu²⁺(aq) + 2e⁻Reduction: The displaced silver ions readily combine with the available free electrons to form metallic silver (Ag) that deposits on the copper wire as a grayish film. This is the reduction half-reaction:Ag⁺(aq) + e⁻ → Ag(s)Net reaction: Combining the half-reactions, we get the overall balanced equation:Cu(s) + 2Ag⁺(aq) → Cu²⁺(aq) + 2Ag(s)Since silver ions are reduced to form metallic silver (Ag), which contributes a blue color to the solution, the observed color change is due to the oxidation of Ag.

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Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.

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