[Geddoe]

Write five balanced equations which correspond to the four intermediate reaction steps and the final
crystallization step in the synthesis of Alum from aluminum.
Note: Use only those products from one equation that actually react in the next equation.

Here's the steps:
1. Aluminum metal reacts with water to produce H gas and aluminum hydroxide.

Thus:
2 Al(s) + 6 H₂O_(l) -> 3 H_2(g) + 2 Al(OH)₃(aq)

2. Aluminum hydroxide reacts with postassium hydroxide to produce soluble postassium ions and aluminate ions.

Thus:
 Al(OH)_3(aq) + KOH_(aq) -> K⁺_(aq) + Al(OH)_4(aq)^-

3. Aluminate ions combine with sulfuric acid to produce aluminum hydroxide again, soluble SO₄^2- ions, and water.

2 Al(OH)_4(aq)^- + H₂SO_4(aq) -> 2 Al(OH)_3(aq) + SO₄^2-_(aq) + 2 H₂O_(l)

4. More sulfuric acid is added, aluminum hydroxide further reacts to produce soluble Al³⁺ and SO₄^2- ions and water.

Thus:
3 H₂SO_4(aq) + 2 Al(OH)_3(aq) -> 2 Al³⁺_(aq) +  3 SO₄^2- + 6 H₂O_(l)

4. Alum KAl(SO⁴)²-12H²O crystallizes when water is cooled enough to cause the soluble ions (of which alum is made) to coalesce and precipitate out of solution.

How can I write this?

[AWK]

Sometimes is more useful to write down full reactions, not ionic one.
K[Al(OH)₄](aq)+ 2H₂SO₄(aq) = KAl(SO₄)₂(aq) + 4H₂O(l)

[Geddoe]

Sometimes is more useful to write down full reactions, not ionic one.
K[Al(OH)₄](aq)+ 2H₂SO₄(aq) = KAl(SO₄)₂(aq) + 4H₂O(l)

Hey thanks for the tip AWK.

Wouldn't that last reaction though be like so...

K⁺(aq) + Al³⁺(aq) +  2 SO₄^2- + 12 H₂O(l)  -----> K⁺Al³⁺(SO₄^2-)₂.12H₂O(s)

And give us the crystal?


Also I'm posed with another quesstion that just states:
Calculate the moles of Aluminum metal.


This seems a big ambigous to me, what should I be looking at (which reaction) to solve this problem?

[AWK]

mass is missing?