Wednesday, January 19, 2022

SI Units for Chemistry Students

What is an SI unit?

What is the SI Unit of mass?

Is ms a metre second or a millisecond?

Is V the symbol for electric potential or volts?

The answers to these and other questions about SI units can be found at https://www.ausetute.com.au/siunits.html

AUS-e-TUTE members should log-in to use the new SI Unit learning resources, including digital flash cards.

Thursday, January 13, 2022

Mass Concentration (m/v)

 There are lots of ways to measure concentration in chemistry.

One method is to divide the mass of solute by the volume of solution: m/v

This is called a mass concentration and common units for mass concentration are g/L or g L-1

AUS-e-TUTE has just added new teaching and learning resources for mass concentration calculations (game, test, drill, quiz, worksheet and problem solving template).

Members should log-in to use these new resources.

Non-members can go to the "free-to-view" tutorial at https://www.ausetute.com.au/massconc.html


Sunday, January 2, 2022

Food Fraud in Australia?

Congratulations to Dr Michael Smith, Associate Professor Mahmud Ashraf, Professor Chris Austin
and Associate Professor Rebecca Lester of  Deakin University on the publication of "Product fraud: Impacts on Australian agriculture, fisheries and forestry industries" (November 2021). This report gives a good, concise, overview of known recent agricultural product fraud from all over the world. While it can make for scary reading, it is a reminder to stay vigilant when buying food. Here is a little taste of what you will find in the report,

"Turmeric is considered highly vulnerable to food fraud, with
frequent incidents of contamination with lead chromate (a
yellow colourant) reported. A study found that seven of nine
turmeric-growing areas in Bangladesh showed evidence
of turmeric adulteration with lead chromate. Levels of lead
exceeded national limits by up to 500 times (24-9-19)."

You can download a copy of the report at the AgriFutures Australia website: https://www.agrifutures.com.au/product/product-fraud-impacts-on-australian-agriculture-fisheries-and-forestry-industry/

Examples of food fraud can be used when teaching chemistry. Students can calculate the concentration of milk or fruit juice after it has been fraudulently diluted, and then compare that to what is stated on the nutrition panel product label. You can learn a lot about the properties of chemical compounds and mixtures by making a fake egg or fake milk. You could used the adulteration of "manuka honey" to teach spectroscopy, or the melamine (1,3,5-triazine-2,4,6-triamine) in milk scandal to teach percentage composition or volumetric analysis. The pedagogical possibilities are limited only by the resourcefulness of the food fraudsters.

If you are looking for some more inspiration, try "Sorting the Beef from the Bull: The Science of food fraud forensics" (Evershed, R., and Temple, N, 2017). And yes, I may have bought it because it has such a great title ... you all know me too well 😉