Chemistry laboratory experiments focusing on students' engagement in scientific practices and central ideas of chemical practices

Two laboratory experiments have been developed to engage students in scientific practices and to central ideas of chemical practices. The experiments are based on the model of pH color scale from plant extracts and its application on acid-base reactions. Three color pH models from red cabbage, radish, and flowers have been developed by students during the first experiment. After evaluating the merits and limitations of each model, the most appropriate pH indicator has been chosen to be used during the second experiment dealing with carbon dioxide production and properties. The activities have been designed in a way that fosters collaboration, decision-making, and the connection of chemistry to the natural world and everyday life. The majority of the materials are household, inexpensive and suitable for both face-to-face performance of the experiments at a school laboratory or for hands on activities on distance learning. The experiments have been implemented in (a) a training course to a group of 23 secondary chemistry teachers and (b) two laboratory lessons to a group of 25 upper secondary students. The activities of the laboratory experiments and the feedback from both teachers' and students' implementation are further described.