CHALLENGES THAT LEAVE THEIR MARK

Understand

Organise your ideas Hierarchical concept map General properties

1 Work with the diagram. Copy the diagram in your notebook and include new branches and boxes based on these ideas:

• Include three examples of simple substances and compounds.

• From the table “Homogeneous mixtures or solutions”, include a branch to describe the particularities of aqueous solutions and another with the concept of concentration and the types depending on the amount of solute present.

• Mass

• Volume

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•

• Decanting

• Filtration

• Distillation

Remember that you can find the answers to all calculation activities on anayaeducacion.es

Properties of matter

1 Indicate whether the following are measures of mass, density, volume or none of the above: a) 3 kg b) 4 cL c) 27 m3 d) 3 g/L e) 690 mm

2 How many 7 L bottles are needed to fill a 3 m3 swimming pool? Could we install it on a terrace supporting a maximum mass of 1 500 kg? Water density = 1 kg/L.

3 Bearing in mind that the thermal conductivity of wood is much lower than that of metals, explain why frying pans are made of metal, while their handles are usually made of wood. Is thermal conductivity a characteristic property?

4 Logic wheel. We have two rods of different materials, both of the same length and volume. If one of them has more mass than the other, can we know which material it is made from? Assume we are given the values of the quantities mentioned in the statement of the problem.

Pure substances and mixtures

5 Classify these materials according to whether they are pure substances, homogeneous mixtures or heterogeneous mixtures: a) Air b) Quartz c) Iron d) Orange juice

6 1-2-4. Indicate the difference between a chemical substance and a chemical element.

Solutions

7 In the laboratory, we prepared a solution containing 70 g of alcohol in 100 mL of water. Indicate which is the solute and which is the solvent.

8 Calculate the concentration of the solution of the previous exercise, expressed in g/L.

9 If we prepare another solution, but in this case using 20 g of alcohol, will it be a more concentrated or more dilute solution than the previous one?

10 Circle of viewpoints. Do mixtures exist in the solid state? Are they homogeneous or heterogeneous mixtures?

11 What laboratory equipment do you need to prepare an aqueous solution of 10 g of salt per 250 mL of solution? What is the concentration of this solution?

12 Nominal group. Can we compare the solubility of two salts in water? Design a method for testing which of the two salts is more soluble.

13 When we prepare homemade lemonade with sugar, sometimes, when we refrigerate it, we notice that there is a large deposit of sugar at the bottom of the container containing the lemonade. Can you explain this? Remember that solubility varies with temperature.

Learning Situation

Reflect

14 The solubility of gases decreases with increasing temperature. Use this to explain why fish are killed by warm water spills.

Separation techniques for mixtures

15 Indicate the names of these materials and whether they are used in separation techniques for homogeneous or heterogeneous mixtures. a) b)

16 Design a method for separating a mixture of oil, vinegar and salt. Explain the material you would use, the steps you would follow and the purpose of each step.

17 On what property is separation by decantation based? Could we separate water from salt using this technique? Explain your answer.

18 We have a suspension of a solid, whose particles have a very small size (powder), in water. We place this suspension in a container and observe that it takes a long time for the particles to settle to the bottom. Which separation technique would you use to speed up the process?

You have created the first part of your poster, so you can start to think about how to improve your skills. Do the self-assessment on anayaeducacion.es and ask at least two people from other teams to assess you as well. When you assess another person, you can indicate their level, but also offer them ideas to improve certain areas.

Aspects Yes With help Not yet

I was able to make a thorough and detailed study of a volcano.

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