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We then went the whole hog, cut the strings, and dunked the chicken legs completely in the acid.
And that was really fascinating.
The chicken leg in HCL and in sulphuric acid just went a bit more - yucky! - if you like.
The solution got darker [in] colour, and the colour is probably due to the pigment, the myoglobin reacting with H+ from the acids.
So it just becomes more light absorbing.
But with HF the chicken leg first of all visibly starts looking almost like shredded, pulled, chicken meat and it goes dead white.
Before it looked a sort of yellowy colour and it looked like corpses - [how] one imagines corpses to look.
This, the meat went absolutely white.
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Off camera: It's starting to, like, de glove. Like the skin's come off.
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And then, at the end, because Neil had to neutralise these - you can't put highly acid chicken legs away -
in the waste -
he dropped them into a solution of carbonate, I think potassium carbonate,
where the residual acid reacts with carbonate to produce carbon dioxide
As the chicken legs were dunked into the carbonate solution they started bubbling.
Now the first thing that was interesting is the leg that had been in sulfuric acid
which had been rather more buoyant than the other legs
it didn't sink as well in the sulfuric acid
but once it got in the water it sank like a stone.
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Off camera: Huh! That one floats!
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The HCL and the HF both stayed near the top.
The HF really bubbled much more, suggesting that the acid
could penetrate much better in the meat.
I mean, after all, a chicken's leg is not just meat -
it is highly structured muscle so that the chicken can run around and try and escape the farmer!
But..
all of that structure has been destroyed in the case of the HF.
With the sulfuric acid and the HCL
there has been some destruction but the meat is still recognisable as meat.
But...
essentially with HF it has gone completely white.
And there is more bubbling because this white mass
is now like a sponge and can just absorb much more acid..
So, it's a bit like the chicken leg has turned into a paint brush.
I think this is a really interesting experiment.
In a way it's far more interesting than we expected.
I mean, we went home really disappointed.
You know we had spent all this money on the chicken legs
and nothing happened.
But in the end, I think we learned a lot more about the chemistry than we'd expected.
First of all, the HF seems to destroy the pigments in meat very quickly.
And also what is quite interesting, and you don't normally see, is that the structure of meat, when you remove the pigments, is absolutely white.
Almost like cotton wool or something like that.
So, I think, in the end, it's been quite a good lesson.
I think it's important to stress that this is a demonstration, not an experiment.
We didn't have a hypothesis beforehand - except that it might dissolve.
But, it did have at least the beginning of the scientific method in that we had two control legs so that could notice differences.
If we had just done the leg in HF by itself we probably would have missed some of the most interesting features.
So, the moral is: think what you're doing before you do an experiment - you might learn a lot more.
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