A two to three period analytical chemistry experiment has been developed which allows second year students to explore chemical color tests used to detect adulterated pharmaceuticals. Students prepare several paper analytical devices (PADs) to generate positive and negative controls antibiotics, along with cutting agents such as starch and chalk.…

An experiment to match five white solids with ascorbic acid, citric acid, potassium hydroxide, sodium chloride, and urea is reported here. This 4 h experiment is an integrated practice of two experimental techniques, calorimetry and titration. Students conduct an extensive literature search on the properties of the five compounds and plan the…

Millions of people do not have access to clean drinking water; thus, cost-efficient water treatment systems are vital. Chemists, environmentalists, technicians, and engineers will be the professionals making breakthroughs in this industry. This laboratory experiment aims to introduce undergraduate students to the removal of pollutants from water…

We describe a series of three experiments in which students develop a model system for measuring the LC50 of household substances, using grass seed as the model organism. Students use statistical methods to compare two samples (using chi-square and Student's "t"-tests), conduct a two-level multifactor experiment to look at multiple…

Introductory physics laboratory experiments have typically been employed to reinforce classroom instruction instead of teaching students experimental design. Recent research has shown that lab experiments that focus on experimental practices are more effective at teaching students physics concepts. The experiment described in this paper has been…

For the past century, humans have been increasingly dependent on plastics, but have not developed adequate disposal practices. In this lab, students are asked whether burning plastic for energy seems like a reasonable disposal technique. To answer the chemical aspects of this question, students use bomb calorimetry to quantify the combustion…

A set of inexpensive and pedagogically rich experiments focusing on S[subscript N]1, E1, and E2 reactions have been updated to include modern computational and spectroscopic analyses. The S[subscript N]1 experiment involves treatment of "tert"-amyl alcohol with hydrochloric acid to generate the corresponding alkyl chloride, which is used…

An experimental approach to chemistry is a more meaningful way to learn than the use of textbooks alone. Working in the laboratory helps students understand basic concepts through their active engagement. Here, we present a series of inexpensive and environmentally friendly laboratory exercises on acid-base equilibrium. Their difficulty level is…

We present a sequence of two physics experiments, designed for use with secondary students, which investigate the specific heat of sand, both qualitatively and quantitatively, without a calorimeter. We use two LM35 temperature sensors and an Arduino prototype board for data acquisition. The results are good and allow teachers to discuss the…

The study of gels and their properties is a compelling topic both technologically and scientifically, and should therefore be emphasized in chemistry and material science syllabuses. In the present laboratory experiment, we propose two experiences, aimed at introducing gelation and gel transport properties using silica gels made from sodium…

The concept of equilibrium vapor pressure plays a key role in the general chemistry curriculum; it is among the first and most easily demonstrated examples of equilibrium and frequently caps off the first semester of general chemistry where it illustrates the properties of liquids and intermolecular forces. We report here simple modifications of…

A laboratory exercise for the synthesis of a sulfonated styrene-"co"-maleic anhydride polymer and its application as a stain blocker on nylon-6,10, is described. The effectiveness of the sulfonated polymer to prevent the conjugate base of an acid dye from staining the polyamide is demonstrated. This experiment is designed for…

"N"-Formamides are important intermediates in the synthesis of many pharmacologically active compounds and are used as protecting groups for amines or as catalysts in different reactions. The current "N"-formylation experiment is designed as a part of an introductory organic chemistry course for undergraduate students. The…

The free radical chlorination of an alkane experiment is often used in the undergraduate laboratory curriculum to introduce students to the free radical mechanism, substituent effects, intermediate stability, and the relative reactivity of radicals. In this experiment, students monochlorinate multiple alkanes and analyze the reaction mixture using…

Keto-enol tautomerism is a special example of structural isomerism. In this experiment, 6-chlorofulvene is predominantly yielded during the chlorination reaction of 6'-hydroxyfulvene with POCl[subscript 3] in the presence of DMF. The high regioselectivity of this reaction is dominated by intramolecular hydrogen-bonding and steric hindrance,…