The conical pendulum is a classic introductory physics problem for teaching circular motion--a topic about which students frequently carry alternative conceptions. As teachers provide lessons to untangle these conceptions, it is good to allow students to practice their new knowledge in varied settings. This is one possible experiment that builds…

Cyclic voltammetry (CV) is the most popular electrochemical technique for the study of electrode processes. One of the reasons for its popularity is its adjustable timescale which can vary several orders of magnitude simply by varying the rate at which the potential is scanned. Changing the scan rate affects CV features including the current,…

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…

This paper describes an experiment with two touching rotating disks, whose movement is followed by video analysis. Within the disks' movements, there are intervals with sliding and intervals without sliding, that is, intervals with frictional forces between the touching surfaces and intervals without it. This system configuration allows for…

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…

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…

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…

Magnets are familiar objects and yet magnetism as a concept remains challenging. A casual search of YouTube for magnets reveals a staggering number of videos, interesting demos involving electric and permanent magnets, and entire channels devoted to various uses for magnets. It is far more difficult to find descriptions that can help students…

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…

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…

Take a selection of balls and marbles along to a nearby playground slide and let students investigate factors that may influence how balls accelerate down an inclined plane. Students can make hypotheses in small groups, plan investigations to test multiple possible explanations and draw conclusions about the importance of different variables. 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,…

Germinating a seed is presumably the first experiment made by a child in his life. So, it has an important place both in child's scientific experience and understanding. Despite the significance of the experiment, the literature indicates that students possess various misconceptions related to the concepts of seed and seed germination. So, it is…

Newton's laws of mechanics are a cornerstone in the development of modern science and its learning can be the very first opportunity for students to defy their common sense perceptions and replace them with a more robust world view. However, despite their fundamental importance, many studies demonstrate how difficult is the true comprehension of…