Chemistry teacher Paul Grooby kicks of the lesson with a starter demonstration, adding potassium permanganate to a series of glasses containing different reagents, to start a chemical reaction and get a colour change. Paul then demonstrates the effect of universal indicator, before setting the class the challenge of creating three different solutions. Using different acid and alkalis and universal indicator, the students will need to create three solutions the colour of traffic lights. The students will need to use a trial and improvement methodology to get the right colours. Paul, a chemistry teacher at Woodkirk High School, finds that all students are able to create a red and green colour, but creating the orange solutions tests the most able students.

Video Series: Great Lesson Ideas
Release Date 2010