Test of science

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Test of science

  1. 1.  Never forget the units in a nanswer! 25kg 19ºC 2m  Read carefully the quiestions. Make sure you understand what you are asked.  Water • It’s a liquid at room temperature • It is transparent • It may be salty or not • Chemical formula: H20 (one molecule contains one atom of oxygen and 2 atoms of hydrogen) • Its essential for life • Freezing point: 0ºC • Boiling point: 100ºC • Ice floats in liquid water  Solubility Room temperature Saturated solution: a solution is saturated when it dissolves the maximum amount of solute it can hold Solubility: maximum amount of solute which 100 grams of water can hold at a given temperature. Why do we have to state the temperature when we define solubility? Because at more temperature water can contain more solute. Calculating Solubility 12g. of potassium chloride dissolve in 75g. of water at 60ºC 75g. 12g. 100g. x=100x12 75 A 100g. of water at 60º can dissolve 16g. of potassium sulphate.

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