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## 3 Separation of heterogeneous mixtures ### Filtration Filtration is a technique to separate heterogeneous mixtures formed generally, by a solid insoluble in a liquid. It is based on the passage of the liquid through a filter (paper, fabric, metallic mesh) that retains the solid, but leaves it t...

## 3 Separation of heterogeneous mixtures ### Filtration Filtration is a technique to separate heterogeneous mixtures formed generally, by a solid insoluble in a liquid. It is based on the passage of the liquid through a filter (paper, fabric, metallic mesh) that retains the solid, but leaves it through its pores. It is used in industry (chemical and food) and in wastewater treatment plants, among others #### TALLER *This section appears to be truncated and requires some content guessing.* 1. You will need to obtain juice without pulp. **Step 1:** Squeeze the oranges to obtain the solid juice. **Step 2:** Pour the juice with the pulp over the strainer with a recipient below. * **Material needed:** * Several oranges for juice * Juicer * Fine strainer * Jar * Recipient **a.** What is the function of the strainer? **b.** What kind of mixture is the juice that is obtained in the end? ### Decantation Decanting is a technique used to separate a heterogeneous mixture, in many cases consisting of two immiscible liquids (oil and water, for example). Decanting is based on the different density of the components of the mixture; the denser one is below the less dense one. #### TALLER 2. Perform an experiment to separate water and gravel. **Step 1**: Prepare a mixture of water with the gravel, and let it rest. **Step 2:** Tilt the container with greater care to take the water to the next container, but being careful not to get gravel with it. * Pour the liquid from one container to the other. * Liquid less dense * Denser liquid * In the laboratory, a decanting funnel is used to separate immiscible liquids. **a.** Why should the mixture rest? **b.** Find out if oil is soluble in the sea and what consequences. ### Magnetism Magnetism or magnetic separation is a technique used to separate ferromagnetic materials such as iron, steel, cobalt and nickelfrom other non-magnetic materials. Electromagnets are widely used in the recycling industry for separating raw materials and reducing pollution. **Step 1**: Introduce a mixture of 100 g of cereals with iron and a little water, and beat it for a minute **Step 2**: Introduce the mixture in a hermetic bag, close the bag, pass several passes on the bag, and magnetize it. * **Material required:** * Cereal and iron * Blender * Water * Neodymium magnet * Bag with closings **a.** What effect does moving the magnet over the bag have? **b.** Could the magnet be used to separate pieces of iron? ### Centrifugation Centrifugation is a procedure to separate heterogeneous mixtures formed by an insoluble solid in a liquid with different density. To carry out the separation, the mixture is introduced into a centrifuge. When it rotates at a high speed, inertia drives the denser component towards the outside of the rotation axis to the bottom of the container. #### TALLER 7. Follow the workshop steps and get the lettuce dry. ##### **Step 1** Wash the lettuce and cut it in pieces. Weigh the lettuce on a kitchen scale. ##### **Step 2** Centrifuge the lettuce for a few minutes. Remove and weigh it again. * Why is the scale measurement not equal before and after centrifugation? In biochemical laboratories, centrifuges are used to separate blood components.