An absorption line at 900 nm has been observed in Perspex. Samples of 1 and 2 cm thickness were used and the integrated absorption (line width times peak absorption) of the line was proportionate to the thickness. Facilities for lowering the sample temperature were not available and therefore both measurements were carried out at room temperature.…

Microplastics have been detected in most ecosystems around the world. They affect the environment and organisms in it, including humans and possibly their health. Hence, the analysis of microplastic occurrence in the environment is highly relevant. However, there are only a few practical and easy-to-implement methods published for school use, and…

This paper reports the development and application of a low-cost multifunctional webcam spectrophotometer for the conduct of molecular absorption and fluorometric measurements. The equipment, which costs approximately US$20 to be fabricated, consists of a webcam, a diffraction grating, and a slit, all positioned inside an MDF box. Spectral…

A laboratory experiment has been developed to illustrate the transformation of silver nanoparticles (Ag NPs) in water containing phosphate anions. The experiment, conducted by high school students, involved hands-on learning to synthesize and characterize Ag NPs via ultraviolet-visible (UV-vis) spectroscopy. This was followed by a UV-vis probe of…

This work describes the design, building, and testing of miniature, low-cost LED-LDR colorimeters for absorption-spectrophotometry experiments. It also describes using these colorimeters for simplified context-based-learning (CBL) activities in school teaching laboratories and for public-engagement events. The colorimeters are simple and robust,…

Plants encounter several different threats that affect their well-being during the spring. With chemistry, plants may defend themselves from, for example, excess UV-radiation and herbivores. The defense compounds between plant species vary, which makes it possible to utilize chemistry in identifying the plant species. In this laboratory…

Demonstration of a colorimetric approach for nucleic acid detection represents an attractive educational experiment for chemistry undergraduate students in the time of coronavirus pandemic. Herein, a rapid and vivid detection method that visualizes the presence of a specific DNA sequence is described. The plasmon resonance of gold nanoparticles…

This laboratory experiment, designed for undergraduate nonmajors or advanced high school students, attempts to demystify the technique of spectrophotometry by utilizing a hands-on, real-world approach. Modification of the reaction for the formation of Fe[(bpy)[subscript 3]][subscript 2+] allows students to interact with vitamin C, a compound with…

Remote access technology in STEM education fills dual roles as an educational tool to deliver science education (Educational Technology) and as a means to teach about technology itself (Technology Education). A five-lesson sequence was introduced to 11 and 12-year-old students at an urban school. The lesson sequences were inquiry-based, hands-on,…

In selecting from a repertoire of traditional kinetics experiments, an instructor often has to choose among having students gain experience with the graphical method, the method of initial rates, or a temperature-dependent experiment in which students construct an Arrhenius plot. This paper presents an environmentally friendly bleaching reaction…

Natural products are ubiquitous in nature but do not form a large proportion of the A-level syllabuses in the UK. In this article we briefly discuss a small selection of natural products, focusing on alcohols, aldehydes and ketones, and alkaloids. We then outline two natural product experiments that are suitable for A-level chemistry clubs or…

A very simple protocol for teaching Beer's Law and absorption spectrophotometry using a smart phone is described. Materials commonly found in high school chemistry laboratories or even around the house may be used. Data collection and analysis is quick and easy. Despite the simple nature of the experiment, excellent results can be achieved.

This article describes a combined UV-photometer and fluorimeter constructed from 3 LEDs and a few wires, all held in place with Lego bricks. The instrument has a flexible design. In its simplest version, two UV-LEDs (355 nm) are used as light source and to detect absorption, and a third LED, in the visible spectrum (e.g., 525 nm), is used to…

We demonstrate here a novel laboratory experiment for the synthesis of gold nanoparticles (AuNPs) by using a low energy gold-sputtering method together with a modern, green, and biofriendly deep eutectic solvent (DES). The strategy is straightforward, economical, ecofriendly, rapid, and clean. It yields uniform AuNPs of 5 nm in diameter with high…

Solubility is frequently introduced at the high school and introductory college levels through the symbolic domain using net ionic equations and solubility product constants. Students may become proficient with spectator ion cancellation and skilled with algorithmic mathematical applications of solubility without obtaining a deeper understanding…