1. Leaders in Science Session 3: Everyday Chemistry

2. Have you ever wondered…
Why do glowsticks glow?
Why is the sky blue?
How do handwarmers work?

3. Spice dye experiment
Take a vial of turmeric dye, and a strip of fabric.
Add sodium carbonate solution, to give the required colour. Test the pH of your vial using an indicator strip.
Put your strip of fabric in the vial, give it a shake then leave it in the dye for fifteen minutes.
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4. (yellow colour in turmeric)
Why is there a colour change?
Curcumin
(yellow colour in turmeric)
Base
Base
Curcumin has a chromophore, which reflects yellow light, but absorbs other frequencies.
As a mild acid, curcumin reacts with the base (twice), which modifies the chemical structure, resulting in a compound that reflects red light.
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

5. Have you ever wondered…
Why do glowsticks glow?

6. So why do glowsticks glow?
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

7. So why do glowsticks glow?
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

8. Why is the sky blue?
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

9. Chemical reactions powered by light
Photochemistry uses light to provide energy to perform reactions.
Recent research has used dyes to absorb light, then pass energy to other reactants...
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10. Spice dye experiment
Now return to your dye, and remove the fabric from the vial.
Remove excess liquid with paper towel, and leave to dry next to your vial.
Why do we see these different colours at different pH?
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11. (yellow colour in turmeric)
Spice dye experiment
Curcumin
(yellow colour in turmeric)
Base
Base
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

12. Lindisfarne lavender dyes
On a related note...
Around 700 AD in Lindisfarne, purple dyes were made from plants, with shades fine tuned by the addition of acid.
The choice of acid was...
“aged urine”
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

13. How do handwarmers work?
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

14. How do handwarmers work?
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.

15. How do handwarmers work?
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.
Exothermic crystallisation of a supersaturated sodium acetate solution!
Heating the crystals will reform the solution, so the reaction can happen again

16. Did you know you could… Go to the leaders in science website for more:
Make glue and ‘plastic’ from milk?
Freeze a bottle of water just by tapping it on the table?
Bend water?
Not time for these today, but YouTube is your friend…
Go to the leaders in science website for more:
Coffee, tea (caffeine) and alcohol are drugs many of us use every day.