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Temperature & Solubility. D. Crowley, 2007. Temperature & Solubility. To know how temperature affects solubility. Word-search. Have a go at the particle word-search See how many words you can find in the next five minutes…. Particles Word-search.
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Temperature & Solubility D. Crowley, 2007
Temperature & Solubility To know how temperature affects solubility
Word-search • Have a go at the particle word-search • See how many words you can find in the next five minutes…
Particles Word-search http://www.teachers-direct.co.uk/resources/wordsearches/preview.aspx?puzzle-number=7670
Solubility • Are insoluble substance always insoluble?! • Some substances which are insoluble in one solvent, may be soluble in a different solvent • E.g. salt does not dissolve in petrol, but in water it will!
Solubility • Some substances are more soluble than others • Very soluble substances have a high solubility • Why is it a good idea to wash dishes in hot, rather than cold water (think about temperature and solubility) • The solubility of most substances increases as the temperature does • This means most substances become more soluble in hot water, rather than cold water, meaning it becomes easier to wash our dishes!
Experiment • You are going to investigate how heat affects the solubility of salt in water • What would be a good way to investigate this? • What will be your independent variable (one changed)? • What will be your dependent variable (one changed by exp.)? • What will you need to control? • What equipment will you need? • What do you predict?
Experiment • We could add a known amount of salt to a beaker of water, and record how long it took to dissolve • We could then repeat this, to different beakers of water, at different temperatures • This would show us how temperature affects solubility • Independent variable: temperature • Dependent variable: time taken for salt to dissolve • Control: water type; amount of salt; time of experiment etc…
Results • Design a results table… These are usually the things you have measured This is usually the thing you change Use a pencil and ruler Always include your units (e.g. cm, sec, N etc…)
Results Remember: everything else except the temperature of water is kept constant
Graph • You now need to graph the class results on the board • Remember, the variable you changed goes on the bottom (temperature) and the variable which was changed by the experiment goes up the side (mass of salt added) • You will need to draw a line graph • You will need a title, labels, line of best fit and explanation as to what your results show
Graph Data • How could you use the graph below to predict how much salt would dissolve at 100oC? We could predict that 7.5g of salt would dissolve in water at 100°C