Advocates for civil rights, environmental justice, and movements promoting social justice require data and may lack trust in public authorities, turning instead to academic scientists to help address their questions. Assessing historical exposure to toxic chemicals, especially in situations of a specific industrial source of pollution affecting a…

Nineteen pre-service and in-service teachers taking a chemistry teaching methods course at a university in Hong Kong were asked to take a diagnostic assessment. It consisted of seven multiple-choice questions about the chemistry of the lead-acid battery. Analysis of the teachers' responses to the questions indicated that they had difficulty in…

Many types of batteries power an ever-growing number of devices. Electrochemical devices like batteries and fuel cells can, in principle, exceed Carnot efficiency for energy conversion. In this novel laboratory experiment, students explore the partitioning of the enthalpy change of a battery's electrochemical reaction between useful electrical…

Batteries are valued as devices that store chemical energy and convert it into electrical energy. Unfortunately, the standard description of electrochemistry does not explain specifically where or how the energy is stored in a battery; explanations just in terms of electron transfer are easily shown to be at odds with experimental observations.…

Discusses safety issues in science, including: allergic reactions to peanuts used in experiments; explosions in lead/acid batteries; and inspection of pressure vessels, such as pressure cookers or model steam engines. (MKR)

THID MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION AND MAINTENANCE OF LEAD-ACID STORAGE BATTERIES USED ON DIESEL POWERED EQUIPMENT. TOPICS ARE (1) BATTERY COMPONENTS AND CONSTRUCTION, (2) CHEMICAL ACTION IN BATTERIES, (3) THE BATTERY AND THE CHARGING CIRCUIT, (4) BATTERY CHARGING VOLTAGE, (5) EFFECTS OF…

On the basis of recent advances in battery research and technology, we have developed a novel laboratory exercise centered on an organic--inorganic battery using the redox chemistry of the organic molecule anthraquinone-2,7-disulfonic acid disodium salt (AQDS). Although most commercially available batteries are based on inorganic redox couples,…

THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO FAMILIARIZE THE TRAINEE WITH PROCEDURES FOR SERVICING LEAD-ACID STORAGE BATTERIES USED ON DIESEL POWERED EQUIPMENT. TOPICS ARE (1) ELECTROLYTE AND SPECIFIC GRAVITY, (2) BATTERY CHARGING, (3) STORAGE BATTERY TYPES AND DESIGN, (4) BATTERY CAPACITY RATINGS, (5) BATTERY INSTALLATION, SERVICING, AND…

This concept module on force is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each energy system. This…

An undergraduate laboratory experiment for the volumetric quantitative analysis of ascorbic acid and iron in dietary supplement tablets is presented. Powdered samples of the dietary supplement tablets were volumetrically titrated against electrolytically generated reagents, and the mass of dietary reagent in the tablet was determined from the…

Out of all the complex systems in science education curricula, cellular respiration is considered to be one of the most complex and abstract processes. Students are known to have low interest and difficulties in conceptual understanding of cellular respiration which provides a challenge for teaching and learning. In this study, we took literature…

Background: Previous research has shown positive effects of Omega 3/6 fatty acids in children with inattention and reading difficulties. We aimed to investigate if Omega 3/6 improved reading ability in mainstream schoolchildren. Methods: We performed a 3-month parallel, randomized, double-blind, placebo-controlled trial followed by 3-month active…

A simple 3-h physical chemistry undergraduate experiment for the quantitative analysis of acetic acid in household vinegar is presented. The laboratory experiment combines titration concept with electrolysis and an application of the gas laws. A vinegar sample was placed in the cathode compartment of the electrolysis cell. Electrolysis of water…

Discusses the nature of phosphoric acid, molten carbonate, and solid oxide fuel cells and major features and types of batteries used for electrical energy storage. Includes two tables presenting comparison of major battery features and summary of major material problems in the sodium-sulfur and lithium-alloy metal sulfide batteries. (JN)

Describes a project that involves determining, by coulometry, the energy output of different types and makes of 1.5-volt AA cells as a function of EMF and time. Involves measuring the volume of hydrogen gas collected at the cathode from the reduction of hydrogen ions in aqueous sulfuric acid by a current produced by the discharge of an AA battery.…