T2 Vapour pressure and evaporation
Put four small petri dishes on a moderately warm heating surface (40-50°C) at the beginning of your lesson. Fill them with 10 ml each of
1) water 2) water with a bit of dissolved table salt 3) ethanol 4) salad oil.
Observe what happens during the lesson. Can you sort these compounds with respect to their volatility?
Please enter in the order of decreasing volatility (Water, Salt, Ethanol, salad oil):
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At the end of the lesson, if it is not yet evaporated, switch on the heating plate and heat up the petri dish with the salty water. What happens? What can you conclude about salts floating in the atmosphere? Give an answer in 3-4 sentences.
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