Marissa Rollnick joined me to talk about teaching the gas laws. We started with the usual links to Mindset resources and then moved on to the 5 point teaching strategy and 3 pressure points. Marissa said she refers to the pressure points as the 'big ideas' in the section. She also spoke about the use of Johnstone's triangle when teaching chemistry. | |

At one point, she spoke about '

Let's take a look at the slides.

__C__ows__M__oo__S__oftly' or '__C__hange something,__M__easure something, and keep something the__S__ame'. This was linked to the variables temperature, volume and pressure. In order to examine the effects each variable had on a set amount of gas, we change only one variable (which is also our independent variable), we measure another variable (the dependent variable) and we keep the other one the same.Let's take a look at the slides.

Mindset resources for this section:

- Ideal Gas (2013 Learn Xtra Live show)
- Gas Laws I: Boyle's and Charles' Laws (2013 Learn Xtra Live show)
- Gas Laws II (2013 Learn Xtra Live show)
- Kinetic Theory of Gases (2012 Learn Xtra Live show)
- Gas Laws I (2012 Learn Xtra Live show)
- Gas Laws II (2012 Learn Xtra Live show)
- Kinetic Theory of Gases (Learn Xtra Lesson)

Marissa's 5 point teaching strategy:

- Start with Kinetic Molecular Theory (KMT) and show how it is different between real and ideal gases Use PHET simulations (or other models) to illustrate KMT and gas laws qualitatively before going to the laws
- Deal with Boyle’s law experimentally, then calculations
- Deal with Charles’ law experimentally then calculations – use it as the way to introduce the Kelvin scale
- BRIEFLY treat Gay-Lussac – probably not necessary to name the law
- Treat PV = nRT and then the general gas equation

Marissa's 3 pressure points or big ideas:

- Particulate explanations of the three gas laws are very important to relate kinetic molecular theory to the gas laws
- Understanding the proportional relationships and how they are represented graphically is vital
- Use of simulations/models is very important for understanding

Marissa's good ideas for teaching this section:

- Use PHET simulations
- Look for experiments on YouTube if you don’t have the actual equipment
- Bring out applications of gas laws in everyday life – make hot air balloons, refer to weather balloons, talk about tyre pressure in cars, how pressure gauges work

This show covered tried and tested teaching techniques for this section. Since the show, I've been wondering if there are more exciting experiments to do in a classroom, or different ways of teaching the content. I think I will Google this and post comments if I find anything. If you have anything to add, please do!

Until next time, happy teaching!

Until next time, happy teaching!