This quick demonstration is a highly visual illustration of the use of acid-base indicators to determine pH. Milk of magnesia is mostly a suspension of magnesium hydroxide in water. Magnesium hydroxide is a strong base that readily neutralizes hydrochloric acid. Universal indicator is a mixture of several acid-base indicators. The changing colours of the indicator during this reaction help students to observe the pH changes that occur during neutralization.
In this demo, two polyethylene strips are charged on one end by rubbing with wool. One charged strip is then mounted on an evaporating dish and the other charged strip is used to make the dish spin.... read more
Categories: Teacher Demonstration
This demonstration shows some differences between potable (drinkable) water and non-potable (non-drinkable) water. Variations in temperature, turbidity and pH level also determine the types of... read more