Tollen's Test (Silver Mirror)

RCHO + 2Ag(NH3)2+ + 2OH− → RCOO− + 2Ag + 4NH3 + H2O

نظرة عامة

Tollens' reagent (silver-ammonia complex) is reduced to metallic silver by aldehydes, producing a silver mirror on the test tube walls. The aldehyde is oxidized to a carboxylate. This test distinguishes aldehydes from ketones, as ketones cannot be easily oxidized. It was historically used for mirror manufacturing.

المشاركون

الدور المادة المعامل الحالة
منتج Water H₂O 1 (l)
منتج Silver Ag 2 (s)
منتج Ammonia NH₃ 4 (aq)

مثال من الحياة اليومية

The silver mirror test creates a beautiful reflective coating on glass, and this chemistry was actually used to make mirrors commercially.

الأهمية الصناعية

Tollens' test is used in organic chemistry for aldehyde identification. Silver mirror manufacturing by chemical reduction is still used for high-quality mirrors.

الخصائص

النوع
Redox
قابل للعكس
لا
الطاقة
طارد للحرارة
ΔH
-135,0 kJ/mol

التفاعلات ذات الصلة

Iron(II) to Iron(III) Oxidation by Oxygen Bleaching with Sodium Hypochlorite Copper Reduction of Silver Ion Aqua Regia Dissolving Gold Cerium(IV) Reduction by Iron(II) Chlorine Oxidation of Bromide Copper Oxidation by Nitric Acid Hypochlorite Oxidation of Hydrogen Peroxide Hydrogen Peroxide as Oxidizing Agent (Acidic) Displacement of Hydrogen from Acid by Magnesium

Frequently Asked Questions

What is the equation for Tollen's Test (Silver Mirror)?
The balanced equation is: RCHO + 2Ag(NH₃)₂⁺ + 2OH⁻ → RCOO⁻ + 2Ag + 4NH₃ + H₂O.
What type of reaction is Tollen's Test (Silver Mirror)?
Tollen's Test (Silver Mirror) is a redox reaction.
Is Tollen's Test (Silver Mirror) exothermic or endothermic?
Tollen's Test (Silver Mirror) is exothermic (releases energy). The enthalpy change (ΔH) is -135.0 kJ/mol.