Writing Equations

[Quincy]

1. The problem statement, all variables and given/known data
Write a balanced equation and indicate the reaction type (single/double replacement, decomposition, or synthesis) for each of the following:
a) Sulfuric acid (aq) + potassium hydroxide (aq) -->

b) Zinc (s) + sulfuric acid (aq) -->

2. Relevant equations



3. The attempt at a solution

a) H2SO4 (aq) + KOH (aq) --> K2S (aq) + H2O (L) (double replacement) -- can't seem to balance it though...

b) 4Zn (s) + H2SO4 (aq) --> 4ZnO (s) + H2S (aq) (single replacement)

-- I don't know how to determine whether the products will be s, aq, or L; can someone please explain how to determine that?

[Borek]

SO42- is a verrry stable group.

[chemisttree]

These two examples are not oxidation/reduction reactions so there is no S-2 in the products.

[Borek]

These two examples are not oxidation/reduction reactions so there is no S-2 in the products.

Sorry, but technically speaking second one is a redox reaction. Still, no S2- in the products.

[chemisttree]

Yes, I meant that the SO4 to S-2 redox of course.

[Quincy]

How about this:
a) H2SO4 (aq) + 2KOH (aq) --> K2SO4 (aq) + 2H2O (L) -- double replacement

b) Zn (s) + H2SO4 (aq) --> ZnSO4 (s) + H2 (g) -- single replacement

[Borek]

More or less OK. I mean - reactants and products are OK, and they are properly balanced. First reaction can be called neutralization. In the second - I would rather assume the zinc sulfate is dissolved after reaction, so more like (aq) then (s).