1. deductive! salt, bicarb, pepper and cornflour [copper sulphate big ones]. looking at properties – how can we work out what this is?? – sight, colour etc ?? smell. nOT taste! does it dissolve. how does it react with other chemicals – vinegar. tabulate. then give a sample again of one of them, and they work out which it is.
2.making invisible inks
a lemon juice
b 1/4 iron sulphate and 1cm water [heat]
c 1/4 copper sulphate, 1/4 ammonium chloride, shake [heat]
3. acids and alkali – litmus paper and various solutions. turmeric solution, red cabbage, universal indicator – get a pH ‘rainbow’
1/4 copper sulphate in 2cm, tie small clean nail and immerse for 10 mins
1/4 copper sulphate in 2cm water and iron filings – several hours
1/4 copper sulphate in 2cm water 2cm magnesium ribbon. few hours
5. heating – copper, iron nail, iron filings, magnesium ribbon, tartaric acid on a spoon, citric acid, ammonium cholride in test tube.
add magnesium ribbon – 2cm to 2 cm vinegar warm and red cap. then light match and take off lid…
add magnesium ribbon 2cm to 2cm water briefly boil. clay pot]