In Tollen's test for aldehyde, the overall number of electron(s) transferred to the Tollen's reagent formula [Ag(NH₃)₂]⁺ per aldehyde group to form silver mirror is __________. (Round off to the Nearest Integer).
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Tollen's reagent is a mild oxidizing agent that identifies aldehydes by reducing $Ag^+$ to metallic silver.
In Tollen's test, the aldehyde group (RCHO) is oxidized to a carboxylate ion (RCOO⁻) by the Tollen's reagent [Ag(NH₃)₂]⁺, which itself is reduced to silver (Ag) metal, forming a silver mirror. The half-reaction for the oxidation of the aldehyde can be written as:
1. RCHO + H₂O → RCOOH + 2H⁺ + 2e⁻
In this process, each aldehyde group transfers 2 electrons. Conversely, in the reduction half-reaction:
2. 2[Ag(NH₃)₂]⁺ + 2e⁻ → 2Ag + 4NH₃
Here, each silver ion accepts an electron and gets reduced to metallic silver. Therefore, the overall reaction confirms that the number of electrons transferred from one aldehyde group to Tollen's reagent is 2. Given that the solution should be a rounded value, we observe that 2 is indeed an integer. This matches the expected range [2,2], verifying that the computed and verified value of electrons transferred per aldehyde group is 2.
