What you do
Write a message on the chromatography paper - you can use either a paint brush or a fountain pen. Choose your painting or writing solution from the table of ‘inks’ below.‘ink’ Spray Solution potassium hexacyanoferrate(III) solution iron(III) nitrate ammonium thiocyanate solution Iron(III) Nitrate copper sulphate solution ammonia phenolphthalein solution ammonia - Let your writing dry by leaving it in the air or using a hairdryer.
Avoid spraying your hands! It might be a good idea to wear protective gloves. In any case wash your hands afterwards. Spray your writing with the appropriate spray solution from the table above and see what appears!
The phenolphthalein solution is highly flammable, so make sure there are no naked flames in the lab.
OTHER THINGS YOU CAN DO
Write a secret message to your friend with a combination of ‘inks’. They will have to try both spray solutions to see what you have written!
eye protection must be worn
wear disposable gloves and wash your hands afterwards
HARMFUL
copper sulphate solution
IRRITANT
iron(III) nitrate solution
HIGHLY FLAMMABLE
phenolphthalein solution
