Science Week

[J]

To all you knowledgeable labbies out there, I have a question for Science Week.

As an activity for Science week we are hoping to conduct an outreach program to three very small and rather isolated feeder primary schools in our area.

We would like to bus the students to our school and introduce them to some fun scientific experiments using colour.
We have the smarties chromotography, the food colouring and detergent that makes the colours go wild in milk, the pH indicator one where you pour the liquid into a series of beakers and the colour changes, and probably some others that we haven't thought of yet.

Does anyone out there have some bright ideas for this kind of stuff, simple but engaging for the younger students, maybe using household chemicals they can find in the cupboard at home?

We would appreciate any ideas to make the day more interesting, so they can take home a fascination for what is to come in high school science.

Thanks
Julie

[Robbie]

Ever made fire extinguishers? It does not use colours but uses household chemicals.

You need a spray bottle, tea bag (one with the string) bicarbonate of soda and vinegar. Very carefully empty the tea from the tea bag and replace the tea with the bicarb soda. Pour some vinegar into the bottle and dangle the tea bag inside the bottle being careful not to touch the vinegar. Hold or tie the string to the top of the bottle, screw bottle top on tightly, shake vigorously and invert. When inverted the vinegar and bicarb will mix and foam will come out of the spout.

You can even make a little fire with some paper and match (somewhere safe!!) and then literally put out the fire.

This works well with high school students but use wisdom with the primary school kids as to whether you make a fire or not.

Cheers,

Robbie

[J]

Thanks Robbie

Sounds like fun. We'll give it a try.

Julie

[Sassi]

Slime??? Our yr 7s had a whale of a time making slime with cornflour and foodcolouring. It did get extremely messy though and had to wash ALL the labcoats. But they enjoyed it very much!

[Jazz]

hi
this is great wesite for kids

http://www.abc.net.au/science/surfingscientist/

[Labbie]

Same thing can be done with the wash bottles, that have the tube on the inside. for Fire extinguishers, use a micro test tube, security with wire, can even cover the wash bottles with red like a fire Extinguisher. Have fun.

[lada]

We have a different prac for fire extinguisher.
Put 3 small candles of different height into a large ice cream container. Attach them with bue tac and light them. In a beaker put 2 teaspoons of baking soda then cover it with vinegar. Tilt the beaker over the the icecream cont. but dont pour any froth in. CO2 is heavier then air and will flow into the container and extinguish the candles one by one, the shortest first.
Lada

[J]

These all sound great, guys, and we'll give them a try, but colour is the topic we're aiming for for science week.
Thanks for your ideas
Julie

[Robbie]

Oops! I meant to use wash bottles, not spray bottles, for the fire extinguishers...

Robbie

[Vick]

Hi

Last November there was a topic - pH prac and potassium hydroxide, posted by Lada called "Rainbow Experiment" if you do a search you should find it. I often print any of the 'interesting' 'helpful' posts out and place them into a folder for further reference.

We used this experiment last year when we had our year 6 orientation night, and it is colourful.

Hope this helps.

Vicki

[RosalieM]

I have 2 rainbow pracs which I think I got from here... I'll attach them both. Same thing but different quantities.

[Voice]

We have one whereby you use full cream milk, food colouring and detergent.
1. Pour milk into a petrie dish.
2. Put 3 drops of red at the edge of the petrie dish, where the milk meets the dish.
3. Put 3 drops of blue about 1/3 of the way around the dish.
4. Put 3 drops of red another 1/3 of the way around.
5. Now add 1 drop of detergent in the middle of the milk.

Watch. It's fascinating.
Maree

[Labbie]

Morning fresh is the degerent to use. Some of the cheaper ones do not work so well.

[J]

Thanks everyone!

Your ideas are much appreciated.

Rosalie I printed off your rainbow pracs and they sound perfect for what we are looking for.

Julie

[sunray18]

I have a couple that are great because the colour changes... one is "changing water in wine"..
1. Sprinkle sodium carbonate to coat the bottom of a drinking glass.
2. Fill a second glass halfway full of water. Add ~10 drops phenolphthalein indicator solution to the water. The glasses can be prepared in advance.
3. To change water into wine or blood, pour the water with indicator into the glass that contains the sodium carbonate. Stir the contents to mix the sodium carbonate, and the water will change from clear to red.
4. If you like, you can use a straw to blow air into the red liquid to change it back to clear.
5. The principle is the same as for the disappearing ink formula. Phenolphthalein is an acid-base indicator.
and the other is the oscillating clock... or the Briggs-Rauscher Oscillating Color Change Reaction..look it up on google.. it is the classic one for osciallting reactions which is shown by colour change...I DID have a Blue Bottle one, but cant find it at the moment.. again google may help...

[lada]

I have the blue bottle

12g glucose
12g NaOH
1mL of 1%sol Methylene blue
1L volumetric flask with stoper

Dissolve 12g glucose in 1L water (volume not critical)
Within an hour of class time, dissolve 12g NaOH in the glucose soln and add methylene blue.
Stopper the bottle. After the sol had been standing the blue colour will fade to colourless soln.
Shake the bottle until it turns blue again.

[Jen1]

I posted this reply in the "eosin" thread and then thought it would be useful here too as it could be used as a demonstration for your science week.

Try white agapanthas for the coloured flowers demonstration. The lower part of the stem can be split vertically into four and each part inserted into a test tube with either blue, green, yellow or red food colouring. Place the four test tubes into a taller beaker or gas jar that will give the flower the support it needs, and after a few hours the colours start to appear in the white flowers.
very pretty
Jen

[lizzieb]

Have you got these ones, Julie? Magical Beakers and Blue Bottles.

And what about chromatography paper strips and black felt pens?

MAGICAL BEAKERS

EQUIPMENT:
6 x 600mL beakers
1M HCL
IM NaOH
Universal Indicator
Buffer solution pH7
plastic droppers

METHOD:
Set up beakers as follows:

Beaker 1: 500mL H₂O + Universal Indicator
Beaker 2: 4 drops 1M HCl
Beaker 3: 4 drops 1M HCl
Beaker 4: 8/9 drops 1M NaOH
Beaker 5: 2 drops 1M NaOH
Beaker 6: 10mL buffer solution

Pour all the solution from Beaker 1 into Beaker 2, and so on in sequence.

The colour should change from green to yellow, then red, then blue, then purple,
then finally end up green again.

(From Chem Dems - Tony Sperring - STANSW)


BLUE BOTTLES
1. Place one spoonful of glucose into a small jar and half fill it with alkaline solution.
2. Add one drop of methylene blue, screw the lid on tightly and shake the jar for 15 secs.
3. Put the jar on the bench and start the timer. Record the colour of the mixture.
4. Closely observe the jar for about 2 mins, noting any change and the time at which it occurred.
5. Shake the jar again and record your observations.
6. Pour the mixture down the sink and tidy up.

(When methylene blue is in contact with oxygen it is blue. Shaking the bottle dissolves oxygen into the solution so it is blue. As the glucose takes oxygen from the methylene blue the solutions becomes clear again.
There may be a faint blue line at the top of the liquid, because the methylene blue at the surface is in contact with the oxygen remaining in the jar).

(From St Marys' Conference, 2005)

I have modified them both to use for Orientation Days in the past.

Sounds like you're going to have lots of fun!

[J]

Thank you so much everyone!!
We'll have lots of fun with all these wonderful ideas.

Karma to those of you who accept it!!

Julie

[Sandra Curry]

The pH of household materials such as lemon juice, vinegar, cloudy ammonia etc is colourful. You could make up red cabbage indicator too, if you liked.

Precipitation pracs are colourful. Combinations of 0.1M lead nitrate, potassium iodide, copper sulphate and sodium hydroxide are good - all but one combination forms a precipitate. Using dropper bottles and waste jars minimises the danger of the lead nitrate.

I was doing a prac the other day that I really liked. It involved heating copper carbonate with a Bunsen (not sure if you want them to use Bunsens though) and bubbling the carbon dioxide produced through bromothymol blue via a delivery tube. The copper carbonate goes to black copper oxide and the bromothymol blue goes to yellow. Be sure to remove the delivery tubing from the bromothymol blue after the colour change is observed.

Or you could just blow into bromothymol blue and get it to go yellow.

If they're up to Bunsens, you could always do the flame tests (2% solutions of chlorides of metals, except for copper where I use copper sulphate because copper chloride rusts the spray bottle bits).

Good luck

Sandra