Examples of experimental work that contribute to greener chemistry education.
Introduction
Including green chemistry into science education is of great value, especially in experimental work, which is a significant aspect of science learning at all education levels.
Enhancing science education with laboratory experiments optimized from green chemistry perspectives provides a safer approach to teaching chemistry topics. This approach ensures a safer learning environment by minimizing exposure to potentially hazardous chemicals and reducing the waste generated.
Incorporating green chemistry principles doesn’t have to be an all-or-nothing approach, but rather a striving for “the more, the better”. To help students develop their green chemistry skills, teachers can ask questions such as “What is (not) green about the experiment?” and “How could this experiment be made greener?”. Teachers should also bear in mind that incorporating green chemistry into their lessons can promote systems thinking, and life cycle thinking.
Examples
In the experiment, the components of a mixture of two liquids are separated by distillation and identified using their boiling points. Before this experiment, students learn how to use safety data sheets and to carry out a risk analysis for laboratory experiments.
Keywords: distillation, boiling point
Age group: 16–17 years old
In this activity, students will gain understanding that the reaction between acids and base metals generate hydrogen gas. They will also discover that the rate of this reaction is influenced by the particular combination of acid and metal involved, as well as the concentration of the acid. In addition, they will develop skills in optimizing a laboratory procedure to ensure that the chemical reaction proceeds at an appropriate rate, while minimizing any potential hazards associated with the chemicals involved. As part of their evaluation of the experiment, they will apply green chemistry metrics, such as the green star rating system
Keywords: hydrogen gas formation, optimize a reaction
Age group: 16–17 years old
This teaching unit is available in two versions, step-by-step instruction, and guided inquiry-based learning. Students will learn about methods for determining pH through experimental work and by using textbooks and other available sources. Using a life cycle analysis, they will evaluate different ways of determining pH according to the methods’ impact on society and the environment. They will also evaluate the experiment using green chemistry metrics (green star).
Keywords: acids, bases, indicators, neutralization, pH determination, salts
Age group: 14–15 years old
Step-by-step version:
- Student worksheets: Getting to know the chemical nature of everyday substances (Word)
- Teacher guide: Getting to know the chemical nature of everyday substances (Word)
Inquiry version:
- Student worksheets: Getting to know the chemical nature of everyday substances (Word)
- Teacher guide: Getting to know the chemical nature of everyday substances (Word)
Appendices for both version:
In this activity, students make observations about several chemical reactions and compare how well these reactions follow the principles of green chemistry.
Keywords: chemical equations
Age group: 16–19 years old
Students will learn about phosphate recovery from wastewater treatment. Phosphorous minerals, that are used to make commercial fertilizers, are a finite resource. Just like in animal manure, phosphorus is found for example in the feces that we flush down the toilet. The students will learn about how the wastewater treatment plants can become resources for phosphorous recovery, by treating and using sewage sludge. The students will use separation techniques including precipitation and filtering. The principles of green chemistry are represented by the focus on the recovery of finite resources.
Keywords: finite resources, precipitation, recycling of chemicals, solubility, wastewater treatment
Age group: 10–19 years old
Students develop knowledge about different properties of alcohols such as solubility and combustibility. They will also learn how to compare the greenness of two laboratory procedures. In one of the procedures, the most hazardous alcohols are either substituted or excluded. The students then evaluate whether they will recommend replacing one procedure with the other. Moreover, they will develop skills in how to use principles of green chemistry to evaluate which of two laboratory procedures is most sustainable.
Keywords: properties of alcohols, substitution
Age group: 16–17 years old
Students will synthesize and analyse three bioplastics, in a safe and systematic way, and compare the degradation to commonly used plastics. Spectrophotometry is used as the analytical method to follow the degradation. Theory of chemical bonding is used to discuss the degradability of the synthesised bioplastics. The green chemistry principles are represented focusing on the use of renewable raw materials and design for decomposition.
Keywords: Bioplastics, chemical bonds and degradation, sustainable development, spectrophotometry
Age group: 16–19 years old
This teaching unit is available in two versions, step-by-step instruction, and guided inquiry-based learning. Biodiesel is made through a chemical process called transesterification. Students will learn about this synthesis through experimental work and by using textbooks and other available sources. Using a life cycle analysis, they will evaluate different fuels according to their impact on people and the environment. They will also evaluate the experiment using green chemistry metrics (green star).
Keywords: alcohols, esters, hydrocarbons, organic oxygen compounds
Age group: 14–15 years old
Step-by-step version:
- Student worksheets: Synthesis of biodiesel from vegetable oil (Word)
- Teacher guide: Synthesis of biodiesel from vegetable oil (Word)
Inquiry version:
- Student worksheets: Synthesis of biodiesel from vegetable oil (Word)
- Teacher guide: Synthesis of biodiesel from vegetable oil (Word)
Appendices for both version:
This teaching unit is available in two versions, step-by-step instruction, and guided inquiry-based learning. Students will learn about bioplastic synthesis from banana peel through experimental work and by using textbooks and other available sources. Using a life cycle analysis, they will evaluate different types of (bio)plastics according to their impact on people and the environment. They will also evaluate the experiment using green chemistry metrics (green star).
Keywords: bioplastic, organic oxygen compounds
Age group: 14–15 years old
Step-by-step version:
- Student worksheets: Synthesis of Bioplastic from Banana Peel (Word)
- Teacher guide: Synthesis of Bioplastic from Banana Peel (Word)
Inquiry version:
- Student worksheets: Synthesis of Bioplastic from Banana Peel (Word)
- Teacher guide: Synthesis of Bioplastic from Banana Peel (Word)
Appendices for both version: