There is a video that shows how to pour water onto ice and it will freeze on contact. I wanted to to try and reproduce this trick (science experiment?) but I've not had any luck.
I will link to the video below but the basics are:
They use distilled water which has a much lower freezing point because there is no neutron in the water to activate the freezing effect. When the water comes into contact with ice it instantly freezes (pretty cool effect), this can be done by putting the ice into the water or pouring the water over the ice.
I've not had any luck getting distilled water from local supermarkets but I did read that deionised water is pretty much the same thing. I just tried it and whilst it didn't really freeze like normal water (it was large crystals that broke easily) it did freeze and what water there was remaining didn't freeze when poured on water.
Now, there are a couple of things I did different from the original video:
1) I used an empty mineral water bottle which was emptied and throughly dried out in an airing cupboard (would this still contain the neutrons required for the freezing process...?), the reason for this is the deionised water comes in 5 litre bottles and for the purpose of the 'trick' that wouldn't work.
2) In their video they froze for 2 hours 45 mins at -24 degrees. My freezer is -20 degrees and I checked on it at 2 hours, this is when I found it in its semi frozen state.
Fairly long post there, but he is the video (which is well worth watching) and I welcome any suggestions on recreating this effect.http://www.iflscience.com/chemistry/turn-water-ice-instantly
the bbc did an article on this effect too (who did actually use deionised water but froze for a shorter time):http://www.bbc.co.uk/science/0/23065582