We used phph all the time in chem classes...funny no one ever mentioned that. Though with a group of high school students, perhaps it was for the better. Nice to know, thanks.
Good stuff! Need more simple practical things like that - it is really interesting.
Slight side topic: Bit of "biology" I've been experimenting with at home based on stuff I had lying around. Works really well...
Items: 2l coke/water bottle, 2l Cheap apple juice (preservative free), sachet instant bakers yeast, 100g sucrose sugar, sterlising tablets, balloon.
Steps: Empty coke/water down the drain or gob, sterlise bottle, put everything but the balloon in it, screw lid on and shake for a couple of mins, take lid off, prick hole in ballooon and stick on bottle neck so it inflates, leave in warm cupboard for a week, put a couple of teaspoons of sugar in it, screw normal lid on and shake, leave for 2 days, put in fridge for 4 hours, drink, fall over :)
In case anyone didn't follow, this is a recipe for alcoholic carbonated apple cider. So easy a kid could do it! The part to be careful about is the carbonation step where you put in more sugar and put the lid on. If you put too much sugar its possible that the bottle will explode.
Get a bowl of water, a salt shaker, pepper shaker, and dishwashing detergent (the liquid kind).
Imagine the bowl of water is a swimming pool. Now add some white sheep (salt), and some black sheep (pepper). Finally, add the big, bad wolf (a drop of detergent) and watch the black sheep swim away to safety!
I think this happens because the detergent spreads out a very thin film onto the surface of the water and pushes all the pepper out. The salt is only for effect/imagination purposes. To this day, this still fascinates me.
Ah, I used to love these things growing up. I remember a book I always read at the library but I can't think of the name of hand. It had awesome experiments like making your own dye, growing various types of crystals, recycling rags to make paper, and it got better. Toward the back of the book they got really good with things like making gun powder, making rocket engines, cutting glass bottles and jars using electricity, reusing a tv flyback coil to make big sparks and explode wood. It was an awesome book! Nothing that would be allowed in a library today I'm afraid.
http://blog.jgc.org/2012/03/fun-with-phenolphthalein.html