Experiences

Children should be encouraged

Mihaela Cucos

Romania

High Secondary School

Chemistry

Teaching in class, Laboratory

Direct

Children should be encouraged to become real chemists and act like them: make predictions and test them, do experiments or make observations. Simple experiments speak volumes and most of the times are more important than pages of abstract theory in terms of raising students’ motivation to learn chemistry. One of the simplest experiments which has been very popular with my students is the one which tests the pH of various water samples, such as tap water (different sources- kitchen or bathroom), bottled water, pond water or fish tank water. We used a kit capable of testing pH and various water samples. We filled test vial to appropriate level with water sample. Then we added a few drops of pH solution to test vial. I asked my students to observe any changes and compare the color of the water sample to the test kit color standards.
We talked about the pH, which is a measure of the acidity or alkalinity of a solution. I told them that pH is important to water quality; changes in the level of pH bring about unpleasant consequences and extreme pH values are even hazardous to plants and wildlife. In a lake or pond, the pH of the water is affected by many factors; pollution from nearby communities and industries is one of them.