Writing Equations: Balancing & Reaction Types

[Quincy]

Homework Statement

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) -->

Homework Equations

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]

SO₄^2- 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 S^2- 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).