Microscale Electrolysis: Synthesis of Iodoform, Its Characterization, Faraday's Laws, and Avogadro's Number

Abstract

Experimental procedure for microscale synthesis of iodoform (triiodomethane) through electrolysis of aqueous potassium iodide and acetone; can be used to determine Avogadro's number and Faraday's constant.

Microscale Electrolysis Using Coin-Type Lithium Batteries and Filter Paper

“…A small-scale cell made of inexpensive plastic is useful because the quantity of chemicals required for the experiment can be reduced and students can easily handle the apparatus by themselves. On this basis, several kinds of easy and low-cost experiments have been developed. − In general, the key structure of the downsized apparatuses, or microscale apparatuses, is almost the same as that of the original ones although the size is different. This means that most small- or microscale apparatuses are made by isotropic downsizing.…”

Using Mole Ratios of Electrolytic Products of Water for Analysis of Household Vinegar: An Experiment for the Undergraduate Physical Chemistry Laboratory

“…Electrolysis of water and stoichiometry of redox reactions are essential to high school and undergraduate chemistry courses. Many reports − demonstrate the electrolysis of water and its pedagogical significance in chemistry. Traditionally, Hofmann apparatus or similar handmade devices have been used to demonstrate the relative proportion of gases produced as a result of the electrolysis process. − ,,− ,,,,− Several indicators have been used to colorfully illustrate ,,,,− the pH changes during the electrolysis process.…”

“…There are relatively few reports of electrolysis involving quantitative assessment of the gases produced at the respective electrodes. ,− These quantitative experiments include determining Avogadro’s number, , optimizing the electrolysis conditions, , and determining the fundamental electronic charge . Silver-based coulometry played an important role in the early development of electrolytic chemical analysis. ,, In these methods, the quantities of electrolytic products were determined exclusively from the mass of silver metal deposited on the electrode.…”

Coulometric Analysis Experiment for the Undergraduate Chemistry Laboratory

“…The coulometric methods of chemical analysis are well-known, and undergraduate experiments based on coulometric methods are common in the quantitative analysis course. Numerous reports on coulometric methods with the pedagogical objectives have appeared in this Journal . − A variety of forms of a coulometry cell made of glass have been reported, and special care is required to clean and assemble the parts of a cell made of glass. The volume of the electrolyte used in these cells is in the range of tens of milliliters or higher. − The coulometry autotitrator cells are expensive .…”

“…Numerous reports on coulometric methods with the pedagogical objectives have appeared in this Journal . − A variety of forms of a coulometry cell made of glass have been reported, and special care is required to clean and assemble the parts of a cell made of glass. The volume of the electrolyte used in these cells is in the range of tens of milliliters or higher. − The coulometry autotitrator cells are expensive . A “salt bridge” is often used ,,,,− to physically separate the anode and cathode compartment contents and to allow the current to flow through the cell.…”