Calorimetry is a central concept in the first semester general chemistry curriculum, and constant pressure (coffee-cup) calorimetry is a common experiment in the laboratory. However, constant volume (bomb) calorimetry is traditionally reserved for the physical chemistry laboratory. This article describes the advantages of incorporating bomb…

The ideal gas law, "PV = nRT," is one of the simplest physical laws in nature that is introduced to students as early as in high school and first year in college. In this equation, "P" stands for pressure, "V" is the volume, "n" is the amount expressed in mole, "T" is the temperature in Kelvin…

Various experiments on vibrating gas columns and on frequency measurements with glasses and pipes have been presented in recent years in the "iPhysicsLabs" column. The determination of the sound velocity in different gases by measuring the sound running time has also already been proposed in an earlier paper. This article now adds…

Organizing undergraduates in chemistry, energy engineering, and chemical engineering specialties to participate in an energy transformation experiment can encourage them to think about the impact of human activities on nature and stimulate them to learn more about the topic. This laboratory experiment demonstrates a general approach to the…

Archimedes' principle is one of the foundation subjects in physics. Normally the principle is exemplified by reference to floating boats. However, Archimedes' principle also applies to objects embedded in waterlogged ground, which can lead to the surprising result of an object weighing several tons being lifted. A practical example is presented of…

In this article we consider a well-known simple, very accessible demonstration of surface tension with a small boat propelled by substances that change the surface tension of water. A simple quantitative evaluation is provided that matches well with experimental data. A modification to the experiment is proposed allowing it to continue for a long…

Thermal conductivity is generally the tool of choice for quantification of fixed gases, particularly lighter-than-air gases. Unfortunately, gas chromatography-thermal conductivity detectors (GC-TCDs) are difficult to introduce in first- and second-year chemistry courses where the cost and number of instruments, as well as the space required, is…

Biodiesel is an important biomass, largely employed in the transport sector and produced from vegetable oils. Additionally, waste cooking oils may be reused to produce biodiesel fuel, minimizing environmental pollution. A laboratory experiment that affords a widespread way to discuss degradation concepts and tools for used vegetable oil…

In the activity described in this communication, the authors present a simple experiment that can be implemented with moderate operational costs and that allows students to acquire the manipulative skills necessary for chromatographic analysis of a familiar fuel that still plays a fundamental role in providing energy for transport of passengers…

A modular experiment for upper-level undergraduate students is presented, featuring the product cycle and process evaluating the quality and quantity of biodiesel obtained from a microalgae feedstock grown under carbon-supplemented and nutrient-deprived conditions. Batch reactors are used to cultivate and harvest microalgae, which undergo…

A safe, convenient, and environmentally benign laboratory experiment for the synthesis of biodiesel from six kinds of vegetable oils has been developed for the introductory organic chemistry laboratory. The experiment uses ultrasonic irradiation in the presence of a base catalyst at room temperature and atmospheric pressure. Because of safer and…

An experimental procedure is presented that was developed by fifth-year chemical engineering and industrial chemistry undergraduates at the Federal University of Rio de Janeiro doing the discipline on Experimental Organic Technology. The aim of this study was to apply the solvatochromic effect of the dye Nile Blue chloride to the characterization…

In this laboratory experiment, students performed thermogravimetric analysis (TGA) coupled with mass spectrometry (MS) of herbaceous materials (TGA-MS) and learned to analyze mass-loss curves, as well as identify common fragmentation ions. The experiment is the first one to present the application of TGA in a currently relevant topic: biomass…

The "safety lamp" invented by Humphrey Davy in 1815 utilised the cooling effect of metal gauze to prevent the flame of a candle or oil lamp (essential for illumination in mines) from passing through such a screen. It is therefore rendered unable to ignite any potentially explosive mixture of air and methane in the atmosphere surrounding…

We describe an activity that is suitable for high school students and makes use of plastic bottles. This activity allows students to familiarize themselves with gas chemistry by introducing technologies that were applied in old submarine systems. Plastic bottles, which are representative of submarines, are used as reaction vessels. Three simple…