Water, one of the simplest substances on Earth, exhibits interesting properties that are not predicted by looking at the trends of the periodic table. However, chemical bonding – a foundational concept in chemistry – and the intermolecular forces that occur between water molecules can explain these anomalous properties. In fact, the properties of all materials can be explained by the way their atoms are bonded together, as well as the intermolecular forces that exist between molecules. Student understanding of these submicroscopic concepts can be enhanced by constructing compounds using molecular models, demonstrating how different types of bonds and intermolecular forces contribute to the behaviour of materials.

As the population of Earth and the demand for resources increases, chemists are increasingly expected to use their knowledge of materials to ensure a safer and greener future for our planet. Therefore, the 12 principles of green chemistry were developed as a framework to design more sustainable chemicals, processes, and products.

In the first part of this program, students examine the bonding in water and examine the concepts of polarity and hydrogen bonding. They create ionic lattices and investigate how many ionic substances can dissolve in water. They use these concepts to make predictions and explain everyday phenomena. In the final session students will create a sustainable solvent using a renewable feedstock to demonstrate how chemistry is contributing to the transition to a circular economy.

Note: Maximum 1 class per day

Students should have covered atomic structure and electron configuration.

In this program students will:

• Consolidate their understanding of covalent bonding, ionic bonding, polarity, and intermolecular forces.
• Be able to explain the properties of ionic and covalent compounds through applying their understanding of intramolecular and intermolecular forces.
• Become familiar with an application of green chemistry by extracting a sustainable solvent from a renewable feedstock.
• Develop their wet lab skills.

Students will:

• Construct covalent compounds and ionic lattices and demonstrate the dissolution of polar compounds in water using molecular model kits.
• Conduct simple experiments to investigate the properties of water and ionic compounds.
• Observe what happens to polar and non-polar molecules in different solvents.
• Extract limonene from citrus fruits to demonstrate a solvent that can be made from renewable feedstocks as part of a circular economy.

Ecolinc Learn Online is a virtual outreach learning management system (LMS) offering interactive online courses for students and teachers. These courses can be undertaken either as a pre-visit, post-visit or stand-alone.

Students are encouraged to do the pre-learning course on Ecolinc Learn Online called Safe Labs prior to coming to Ecolinc. In this course students will cover all the necessary aspects of laboratory safety during their time at Ecolinc. When planning any work in a laboratory the risk of exposure to laboratory hazards is an important consideration. This course is part of Ecolinc’s risk minimisation for student safety.

Area of Study 1: How do the chemical structures of materials explain their properties and reactions?

Covalent substances

• Polar and non-polar character with reference to the shape of the molecule
• The relative strengths of intramolecular bonding (covalent bonding) and intermolecular forces (dispersion forces, dipole-dipole attraction and hydrogen bonding)
• Physical properties of molecular substances (including melting points and boiling points and non-conduction of electricity) with reference to their structure

Ionic compounds

• The common properties of ionic compounds (brittleness, hardness, melting point, difference in electrical conductivity in solid and molten liquid states), with reference to the nature of ionic bonding and crystal structure

Separation and identification of the components of mixtures

• Polar and non-polar character with reference to the solubility of polar solutes dissolving in polar solvents and non-polar solutes dissolving in non-polar solvents

Area of Study 3: How can chemical principles be applied to create a more sustainable future?

Sustainability

• Sustainability concepts and principles: green chemistry principles, sustainable development, and the transition from a linear economy towards a circular economy