Hi everyone, welcome back to Cody's Lab!
so tomorrow is mother's day and I happen to know that my mom needs measuring cups
so I went and bought her some steel measuring cups as you can see here
now, this is a little bit boring so I thought "why don't I do something interesting,
say, plate them in gold"
so, lets dissolve some gold
I 've got a little bit of gold here from my gold bullet project
this is just little scraps that I had left over
from when I cut the bullet to shape after casting it
you can see here I've got quite a bit of gold actually
I think I've got over a [little] more over half an ounce right there
It's mixed with some paper bits
so I'll try to select the pieces out that don't have paper on them
so there's actually an easy way to seperate the paper bits from the gold
thats just to blow on it
the gold is very dense so it will stay put while the paper will blow away
there we go
looks like I lost a few pieces but I caught them back on this paper here
alright, so that's actually probably way more gold than I need, but it's not going to hurt to have too much
now I'm going to add some hydrochloric and then nitric acid
so now the nitric acid don't really need that all that much
the nitric acid is just to oxidise the gold so that the hydrochloric can dissolve it
you can see the solutions colour is changing a little bit already.
the gold is dissolving
so I just dropped the anvil on my foot
fortunately I was wearing steel-toed boots
and uh, It didn't hurt my toes at all, although the shoe
It's got a little bit of a rip in the leather
these were old boots anyway
but yeah, thats one reason why I always wear steel-toed boots when I'm working around stuff
anyway, while that gold in there is dissolving I wanted to take a piece of this, one of
these chunks of gold and kind of stretch it out into a long rod that I can use as
my positive electrode
ohh, its crumbly... i'ts crumbly gold.
hello, hello puppy might have to remelt the gold or at least anneal it so it's softer
smelting it seems to work so I'm just going to melt it together into a long strip
that'll do so that's actually a nice little gold bar very heavy my guess is right
around 10 grams so that's about $300 worth of gold anyway here's the solution
looks like it's mostly all dissolved so now I'm going to take this, I'm gonna
pour it into the larger beaker and that'll leave behind all the sand and
stuff so rinse this out with a little bit of water
okay so now we've got to get the gold into a form that is usable for
electroplating I could electroplate with this but it would form gold that was...
it wouldn't be a flat layer it would just kind of bunch up in to gold crystals so
I need to convert this into a cyanide solution one way I know to do that is to
neutralize it and form gold hydroxide the gold hydroxide is soluble in cyanide
and doing it like this I don't have to evaporate the solution down or turn it
into a metallic powder
and there you go there's the gold hydroxide forming, should be a
brown powder so now that I've got the solution neutralized and diluted I'm
going to add a little bit of sodium hydroxide to make a very caustic
solution with some sodium cyanide
let's take a chunk of this out let's put this in and
dissolve it up cyanide of course will dissolve the gold
hydroxide into gold cyanide which is soluble now I'm going to add the sodium
hydroxide cyanide solution to the gold hydroxide now hopefully that goes clear
it's definitely going clear you can see it changing color looks like it's going to take
a little bit might even need a little bit of dissolved
oxygen to make it work so it will take some time before this is completely
clear in fact I think it does produce some amount of metallic gold
as the cyanide reacts with hydroxide but the metallic gold should dissolve over
time as oxygen mixes in the solution so while we're waiting for that let's clean
these cups off so the gold will stick properly let's make us a little bit of a
dilute hydrochloric acid just give these a good dunk clean off surface
contamination and oils now that they've all been blasted with a hydrochloric
acid and the surface should be clean I'm going to neutralize them with some
sodium hydroxide that way I'm not
reacting the acid with the cyanide which would of course make hydrogen cyanide
gas which is a little bit more dangerous negative to the thing I want plated
positive to the gold so what's happening here is the electrons are going into the
negative electrode and they're reducing the gold at the surface of the metal at
the positive electrode electrons are being taken away this oxidizes the gold
so it dissolves into the solution as you can see we're getting a layer of gold on
the surface of the part I might have to go find some alligator clips or
something so I don't have to sit here and hold this is going to take a
little while I can just let it sit here for long periods of time and when I need to
I can take it off and move it around so I can get the other side this is going
to take a little while to get these all processed it should look cool when
they're done. Ok so here's the big one we just let it sit in there for about 20
minutes let's go take this out rinse it off and see what else needs to happen
with it it seems like I'm going to have to dip them multiple times
they're getting shiny it's hurting my eyes I'm just going to blot
this dry it seems to do better when it's dry it's like it helps the gold stick to
it like once it dries out then I can get it wet again and it won't be a problem
it's almost like the water keeps the gold from sticking so what I've been
doing is after the first dip in the electrolysis solution just lightly rub
it with some steel wool if the gold comes off I'll know that I've got to rub
that area to clean it and then dip it again it looks like this back portion
here the gold is pretty thin so I'm going to move over to here to the side
look at that it actually takes a polish steel wool does quite well for this
like see here where the gold has rubbed off so what I'm going to do is take the steel
wool and just rub this really hard right there to take whatever was keeping the
gold from sticking hopefully remove it in that spot now when I put it back in
the gold should be better able to stick to that location seems to be doing
pretty good on this side right here though the steel wool's probably pretty harsh
but I want to make sure it stays on I don't want this coming off through
ordinary use Kanyon's got a little bit softer touch than me so I'm having her
finish them up. How's it looking?
"pretty good"
yeah no major bare spots?
"I don't think so"
that's all holding up to the scrubbing
looks good so there it is four measuring cups plated in 24 karat gold how about that
there's still a few spots that the gold never did stick I never could get
it to stick in some of the certain areas and also being 24 karat gold it is fairly
soft so it will wear off in places I'm sure excessive scrubbing will remove the
gold layer but it should hold up for normal use any way let's say we should
go give them to my mom hey there
"hey"
I'ts a day early but I need to put the
video out so
"Alright let's see what you got"
"oh my gosh they're gold that is super cool"
"how in the heck did you do that?"
little bit of chemistry magic.
"look how cool I won't dare use them though, that is awesome!
I won't have to worry about them being taken out of my cupboard being used for
another chemistry experiment. That is super cool, very awesome"
"Thank you!" No problem.
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