what I have is some barium hydroxide okay and I'm going to put this into the in fact you know what I'm going to do this in one of the beakers not that thing because it's ridiculous bar hydroxide and I've got some ammonium chloride now what I'm going to do is mix these together and hopefully we should see a endothermic reaction yes this with the hand stuff what hand stuff the hand sanitizer oh it just lives on my desk I was chopping up Hearts earlier and yeah I need to be not covered in blood so what I'm goingon to do to show how exothermic this is how much heat this is taking in so I'm going to make this wooden block wet okay now um you will see why I've done that in a second so I'm going to mix these two things together and carefully um bit mix these two things together well hopefully not because if it's blowing up and giving out huge amounts of energy like that that would be what Ty reaction exothermic now we want to see endothermic so it's going to be a little bit more subtle so I mix the B hydroxide and ammonium chloride together it fre and they should start to react does it freeze it well we should soon see so they're mixing together now can you see how the consistency of that is changing slightly it's of clumping together cuz one of the products it's making is water in this reaction and you can see actually that's all gone liquid and it was all just solid powders it's not milk you wouldn't want to okay you put that in coffee be in problems now one of the products of this because it's ammonium chloride is it's giving off ammonia which smells rather horrible and I forgot about that which is why I Just Breath the H in um that sort of horrible slightly Tangy smell in we is um sort of ammonia light oh is that what I can smell yeah that's what you can smell unless you've wet yourself that is can smell okay but also actually I'm this is getting actually very cold as it's going along okay now hopefully if this is worked it's getting cold enough well you know I put water on the base there yeah fingers crossed it's frozen the water onto the Bottom now this reaction has worked so well so much energy has had to be taken out of the environment it's got that water so cold that it's dropped below freezing and Frozen onto the bottom that is pretty cool uh well I Haven got in fact I have got a thermometer I'm an absolute liar so I can put that there um then is dropping down to well we know it's below what zero so ume this thermometer is calibrated to minus 10 it's shot down to minus5 by about now um and it's carrying on going will it freeze our fingers uh if you heard it on there yeah it would start to in fact there's actually ice crystals forming on the side can I touch cool yeah uh no