A Student-Made Silver–Silver Chloride Reference Electrode for the General Chemistry Laboratory: ∼10 min Preparation

A student-prepared silver–silver chloride reference electrode is described. The chemical deposition of AgCl(s) onto Ag(s) is accomplished in 30–50 s by placement of a Ag(s) wire in laundry bleach. An autopipettor tip with an agarose gel plug serves as the electrode housing; the agarose gel contains predissolved KNO3. Reference electrode preparation is completed in about 10 min, allowing enough time for laboratory exercises that utilize the electrode. Preparation and operation of the electrode and recovery of the Ag(s) are designed to teach a number of important chemistry principles.