HCL/CL Spent Acid, after the leach?

[butcher]

Just to make this a little more confusing:

Say I use new acid HCl and add zinc.

Make notice of your reactivity series chart, zinc is above hydrogen in that list.

This means zinc will replace hydrogen from the acid and make a salt (acid and metal= salt of that metal) in a solution of water, now you no longer have an acid of hydrochloric acid but you have a salt of zinc chloride in solution.

Notice chloride ends in (ide), meaning a salt of (or made from) hydrochloric acid; this salt is not an acid.

Lets look at this experiment, mix two very strong chemicals, each one very dangerous, and can burn you, both would be very bad to taste, hydrochloric acid (HCL) and sodium hydroxide (NaOH), (caustic soda) or (lye), this will give us a salt of the metal sodium,
HCl + NaOH --> NaCl + H2O
So we made table salt we could eat on our French fries,

Now we no longer have a strong acid or a strong caustic.

 

[awbrew]

That is so cool, Butch your alwesome! I really love this forum! Theres so many of you guys on here, that would be dangerious if trapped in your kitchen or the bathroom. LOL

 

[freechemist]

Palladium wrote:

"Let me see if I can explain. As Dtectr pointed out look at the reactivity series. Think of your acid as a battery. That battery only has a certain amount of energy stored up and can only do X amount of work before the energy is depleted."

This statement is only partly correct, because the whole system, the sum of dissolved metal-ions which can be reduced by metallic zinc and the total acid have to be regarded as a battery. In HCl it is the hydrogen-ion H(+), which is reduced by metallic Zn to elemental hydrogen:

2 H(+) in solution + Zn(metal) => Zn(2+) in solution + H2 gas
Cu(2+) in solution + Zn(metal) => Zn(2+) in solution + Cu(metal)
Pt(IV) in solution + 2 Zn(metal) => 2 Zn(2+) in solution + Pt(metal)

All reactions occur at the same time, but with different velocities, depending on individual concentrations and redox-potentials of reducible reactants. In addition, reaction products like metallic Cu formed primarily through reduction of Cu(2+) with Zn(metal) will reduce precious metals too. By far the fastest reaction at higher acid-concentration is the oxidation of metallic Zn by hydrogen ions to dissolved Zn(2+) and parallel generation of hydrogen-gas (H2). Hydrogen-gas itself is also able to reduce dissolved precious metals, itself being reoxidized to hydrogen-ions H(+).

freechemist

 

[nōnāgintā trēs]

So long as there's no gold left, I'd use it to clean the toilet!!

 

[NoIdea]

So long as there's no gold left, I'd use it to clean the toilet!!

Don't spill it on the seat as it will dissolve your jewels. :mrgreen:

 

[gold4mike]

:shock: :shock:

 

[NoIdea]

Thanks Skippy... One small Question ? If I dropped the Zinc, With say aluminum would the zinc still be pure? ( I would think not.) Seems what I learned so far from Cementing is it will bring metals down, but usually isnt that pure. Is that correct?

Not sure if your Aluminium Zinc question was actually answered, sooooo, .... zinc is way to reactive to be dropped by aluminium, the higher you go up the reactivity series the less likely they will be dropped as a metal, iron for example is not reduced to iron, butt the salts of iron in a higher oxidation can be reduced to a lower oxidation state (ferric to ferrous for example) or visa-versa. Dropping gold using ferrous sulphate changes the oxidation state of the iron to ferric sulphate.

Just a case of moving those little electrons around.

Hope that helps

Deano

 

[butcher]

Aluminum forms a gel in HCl the aluminum really does not dissolve well and may not supply the zinc with electrons needed to reduce the zinc from solution to metal zinc, so you would probably end up with a zinc chloride solution full of aluminum gelatin in solution.