Separation by Filtration and Sieving - Presentation

In a presentation designed to teach about separation techniques in chemistry, specifically filtration and sieving, students are prompted to consider how solutions are formed and the best methods for separating their component parts. The presentation sets the scene in a coffee shop where a new barista, Sadio, learns about making coffee and the importance of using intact filters to prevent coffee grounds from ending up in customers' cups. This real-world example illustrates the concept of solubility and the function of filter papers, which have pores that allow soluble substances to pass through while retaining larger, insoluble particles. Students are then asked to identify the solute in coffee making, understand what pores are, and consider the consequences of using damaged filters.

Further exploring separation techniques, the presentation guides students through an experiment using a colander and sieve to separate a mixture of marble, rice, and water. This activity demonstrates the practical application of sieving, highlighting its effectiveness and limitations. Students reflect on why the separation was not perfect and discuss where sieving is used in everyday life. The presentation also delves into an investigation of filter papers, comparing their pore sizes and filtration times, and explaining the need for different grades of filter paper. Finally, a filtration example using sand and filter paper helps students understand the relationship between pore size and particle size, as well as the efficiency of filtration as a separation method. The lesson concludes with questions to assess students' understanding of creating solutions and separating mixtures, ensuring they can apply their knowledge to various scenarios.