There are different types of a luminescence, but all of them are united by one – they cause delight of observers. It is similar to focuses, preparation of the shining liquids is unusual, but has a scientific explanation, and at the correct giving stimulates interest in chemistry. The truth or even in shop of chemical reactants not to do without visit to pharmacy here. But the result is worth of efforts – fascinating experiments not only will help to occupy the child, but also will explain to him what is chemiluminescence.
It is required to you
- Luminal of 2-3 g
- Water of 100 ml
- Peroxide of hydrogen of 3% (pharmaceutical) 80 ml
- Red blood salt of 3 g (or copper vitriol, chloric iron, or 30 ml of a dimethyl sulfoxide)
- 1 N solution of a caustic natr (NaOH) of 10 ml (35 g of caustic potassium, GAME)
- Fluorescent (important!) dyes:
- rubren (red), eosine, fluorescein, diamond green
- 2 test tubes or flasks
Instruction
1. Luminal, or hydrazide of 3-aminophthalic acid, - yellow powder which in neutral and sour solutions gives a blue luminescence. It easily is oxidized peroxide connections in the alkaline environment in the presence of ions with a variable valency (ions of iron, copper, sulfur). Take a clean flask. Pour in it 100 ml of water. Dissolve 2 g of powder of luminal in water.
2. Add hydrogen peroxide to the same flask.
3. Add a pinch of blood salt (K3Fe(CN06). It can be replaced with more available copper vitriol (CuSO4) and also chloric iron (FeCl3), a dimethyl sulfoxide (pharmaceutical Dimeksid). By the way, hemoglobin of blood contains ions of bivalent iron therefore even blood can be used in this experience (as it is used in investigating authorities for detection of traces of blood). But for experience it is enough to take blood from a fresh piece of pork, gammon and to part it with water – there will be enough tablespoon of such solution.
4. Podshchelochite solution, having added a caustic natr. Turn off the light, and you will see how liquid in a flask shines bright blue light.
5. To change a blue luminescence to other color, add dye fluorescent (surely) to solution of any. Diamond green, rubren, eosine will be intercepted by light quanta radiated by luminal and to pereizluchat them at lower frequency, giving other colors.
6. Using a dimethyl sulfoxide in experiments, it is not necessary to dissolve luminal in water as the first is on sale in the liquid state. At once mix caustic potassium in a flask (carefully!), dimethyl sulfoxide and 0.1 g of luminal. Close a flask a stopper and well shake. There is a long, bright blue luminescence (which color can also be changed fluorescent dyes). When the luminescence weakens, open a stopper of a flask and let in a little air – it will amplify again.