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Lesson No: 5 Unit Title: Solutions |
Unit No: 7H |
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Lesson Title: Still water |
NC Ref: |
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Objectives: MK - What pure water is, distillation separates a
liquid from anything dissolved in it. Understand water vapour, steam,
condense, distillation SK - Explain distillation using particle ideas. CK - applied to crude oil, desalination. |
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Lesson outline: Time MK Review evaporation from last lesson
that
it is used to obtain a dissolved solid from solution. As scientists, we often
want the solvent and not the solute Demonstration Heat some ink in
a large conical flask with a watch glass over the top, ask the students if
they can see anything on the underside of the watch glass.
They will see drops of water forming. Lead towards the idea that the water vapour needs to be collected Practical Students to
distil some ink. SS56 shows students the general set up. Demonstration Mix some ethanol
and water in a 1:1 ratio. The 2 liquids mix but have different BPts. Put some ethanol, water and ethanol/water mix on 3
watch glasses. Put a lit splint into each only the ethanol
will catch light. Distil using quick fit. Test the distillate with a lit
splint. Plenary MK Distillation separates liquid from anything dissolved in it. It involves evaporation then condensation. 7Hc/1 and 7Hc/3 SK Use particle ideas to explain the process. 7Hc/3 CK Distillation can
be used to separate liquids of different boiling points. 7Hc/3 Exploring Science P94
97.
7Hc/3
could be used as homework |
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Homework:
7Hc/3 |
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Resources: SS56
7Hc/1
7Hc/3 Conical flasks, delivery tubes for conical flasks,
test tubes, inky water, thermometer, anti bumping granules, large conical
flask, 4 watch glasses, 1 quick fit distillation apparatus,
ethanol, splints |
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Risk Assessment: safety glasses. Anti bumping granules are a must
with all distillations. Ethanol is flammable take care when
heating water/ethanol mix, keep flame away from condenser |
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