Hydrochloric Acid (Part II) - Periodic Table of Videos

well we saw the cheeseburger and that's all fine and well being soft tissue soft flesh and bum but we actually wanted to give it a go with something harder something more substantial so using a regular well-known auction site I managed to purchase a skull a goose skull and we're going to use that and see how hydrochloric acid hydrochloric acid when it's concentrated is dangerous obviously when it's dilute it's not dangerous you've got it in your stomach though if it swells up inside Wells up inside your esophagus the tube that goes from your mouth to your stomach it can cause quite unpleasant pain we've got a big conical flask now and what we're going to do again put some hydrochloric acid in there so what did that first gram is ready with his big tube so what we're doing is we're gonna get into some zinc metal maybe we'll get a little bit more at this time it should f of s quite a bit and gram is ready with the tube to collect it now you can see the effervescence so all the hydrogens should be coming off hopefully in collecting in here what you can actually see though is hydrogen gas doesn't have any color or anything what you're seeing is a bit of water vapor because this reaction here is very hot HCL reacts with metals like zinc and magnesium to produce hydrogen cross your fingers Graham going for it again it's stuck it's stuck yeah that was it that was it that was the prop did you not hear the pop no I think it's because it's in such a big area then to get another get as big a pop when I was at school one of the boys wasn't thinking what he was doing and he added sodium carbonate to his zinc instead of hydrochloric acid so no hydrogen came out the teacher came along and said ah I'll really get this started I'll add concentrated hydrochloric acid now concentrated acid reacts with a carbonate to generate a large amount of co2 gas so the teacher poured in the concentrated acid there was a huge bang and part of the apparatus which was glass shot up to the ceiling and smashed the glass on the ceiling and then came down this is a very good lesson that when you're using chemicals you have to read what the label says on the bottle or you can make a really quite serious mistake we'll see what happens when we add the acid is the Baker so I really quite like to show you a little demonstration in the lab an experiment which when it works is one of my favorite so let's go to the lab and we'll have a look if it is not yet so the skulls been cleaned really well and there's not a single bit of flesh or soft matter left on it it's purely the bone you can see it's actually bubbling away so the bone is reacting with the hydrochloric acid we're going to leave that now I'm expecting that actually to take longer than the cheeseburgers so we'll leave it in there to stew and come back in a bit and see how it how it looks so the reaction is reaction of cobalt chloride and we're going to dissolve it up and then see what happens if I add concentrated hydrochloric acid HCL to it so here is the cobalt chloride you can say the rather nice reddish crystals doesn't quite match my lab coat Oh a piece it's flipped over at some point I didn't see when that happened but it was at an angle like that originally with the beak still there and the head down here and it's now dissolved to such an extent that the whole lot of it can fit parallel to the surface of the liquid so it's clearly changed color and you can still see it bubbling and frothing first of all and go to add water so and it is dissolved and I'm going to put half into this tube so we've got two tubes with the same amount of material so it looks as if there's not much of it left so let's take a look around this side okay so most of the skull has gone the only thing that's remaining there is the beak so if we lift it out and take a look oh okay so from the look of it it's only the beak that's left and there's the jaw let's stuff that up and take a look Oh kind of gloopy so there we go the beak is clearly made of something different from the skull so the skull being bone is mainly calcium phosphate and the beak I think and is mostly keratin so it's a lot of protein and the HCL just hasn't really touched it I mean it's giving it a bit of a sticky layer from the feel of the beak through the tongs but the skulls completely dissolved and it's just in here in the soup so in this one I'm going to put some water and you can see that when I put in some water has got a bit lighter than that because I've diluted it so let's see what happens if we add some concentrated hydrochloric acid so I'll try and add it so we have the same volume in both so we would expect if we add the HCL that it should make the color go lighter but as you can see is gone not only blue but it's gone much darker blue then the pink so we have diluted something and it's got darker and the reason it has got darker is because the chloride ions have reacted with the cobalt so now we have in there cobalt with four chlorine atoms rammed it and to begin with we had cobalt with water around it and chloride ions swimming in solution so I think that this is really quite a nice color change

Channel: Periodic Videos

Views: 286,362

Rating: 4.9466157 out of 5

Keywords: hydrochloric, acid

Id: W7GE56dxS8o

Length: 7min 2sec (422 seconds)

Published: Fri Apr 16 2010

Reddit Comments

[u/Engineroom]

This gentleman is, without doubt, the coolest Professor I've ever seen in academia.