© association for science education and centre for science education 2010 this page may have been...

© Association for Science Education and Centre for Science Education 2010 This page may have been changed from the original

Drunk?Fake! sequence


2

7E Learning Cycle

Students watch the distillation of the

guard’s juice

Was the guard drunk on duty? Did his

orange juice contain alcohol?

Students give initial ideas

Students use the web page to work out a way

of separating the alcohol from the juice

Students write a report on what they have

found out

Students learn about how

distillation works



Objectives:

• Use distillation to separate a mixture of liquids.

• Describe what happens to particles in distillation.

Activity 5: Drunk?3


Activity 5: Drunk?4

Engage Elicit Explore Explain Elaborate Extend Evaluate

Do these particle diagrams show pure substances or

mixtures?

We need to think about pure liquids and mixtures for the next

part of the case.


Activity 5: Drunk?5

So what?

The gallery owner didn’t believe our drugging story. He thinks that the

guard had alcohol in his juice and he fell asleep drunk. He didn't do his job and

stop the burglary. The owner wants to sue him!

We’d better check if the juice has alcohol in it. But how?

Do alcohol and juice have different physical properties?

Let’s do an Internet search.


The crime scene investigators found half a

glass of orange juice on the guard’s desk.


Activity 5: Drunk?6

Everything you need to know about science

ScienceAnswers.comWhat does it mean when we say that something is pure?A pure substance is something that contains only one type of particle. The opposite of pure is a mixture. Pure substances have the same properties.Examples: Pure water contains only water particles. It always has a melting point of 0 °C and a boiling point of 100 °C.Pure ethanol (alcohol) contains only ethanol particles. It boils at 78 °C, it is highly flammable and it is soluble in water.Pure salt (sodium chloride) contains only sodium chloride particles. It has a melting point of 801 °C and a boiling point of 1465 °C. It is soluble in water.If we mix substances together we make mixtures.Examples:Sea water is a mixture of water, salt and other things (like fish!). Because the water has a boiling point much lower than salt, we can get salt from seawater by evaporation.Even though we sometimes call fruit juice pure, it is in fact a mixture of mainly water with other substances.Alcoholic drinks are a mixture of ethanol and water. To make them stronger, the alcohol can be distilled.



Activity 5: Drunk?7


I can show you a simple way of getting pure water from a

mixture.

Did you predict any problems with using this distillation technique for the guard’s

juice?

mixture of ink and water

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8


Activity 5: Drunk?

What state are the the particles in at each

stage?

mixture in the flask

leaving the flask

top of the condenser

bottom of the condenser

SS1/2


9


So, the technique of distillation will separate out

alcohol and water. Whatshall we do next?

Try it out on the guard’s

juice!

OK! But how will we know if there’s alcohol

in the juice?

Activity 5: Drunk?

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Activity 5: Drunk?10

Well, that’s good evidence that the gallery owner’s theory is wrong.

The guard’s juice has no alcohol in it.


Prepare a statement that includes:• what we did

• how the technique works• what would happen to juice with alcohol in it

• what we saw when we did the test.

Make sure your science is spot on, Billie. I've got a feeling the owner is going

to be hard to convince!


Activity 5: Drunk?11

So our evidence proves beyond all reasonable doubt that it was not the

guard’s fault that he couldn’t stop the burglar? Are you sure, Dragon?


Brilliant, Billie. We have used science to prove

that the guard is innocent. There is no way that the gallery owner can

sue him for not doing his job properly now!


Picture Slide Credit

Picture credits

Activity from the Forensics unit © Association for Science Education and Centre for Science Education 2010.Teachers and others who download this material may use it freely within their institution.

For any other usage consult the upd8 team, [email protected] and upd8 are not responsible for any revision that may be made to the material after it has been downloaded.

© association for science education and centre for science education 2010 this page may have been...

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