Answer:
Odd answer choices, but I would put "It shows you that water is a reversible reaction, which contains hydrogen and hydroxide reactions."
Explanation:
The first choice is weird, although water can be written as HOH that doesn't help you understand acids and bases.
The third choice doesn't do that either, and there are more ways for water to be formed than that.
The second choice helps you understand acids and bases, specifically, in water's self-ionization process. It also shows you that it is neutral because it is formed from Hydrogen, which is usually present in acids, and a Hydroxide group, which is usually present in bases.
Answer:
With an understanding of the ideal gas laws, it is now possible to apply these principles to chemical stoichiometry problems. For example, zinc metal and hydrochloric acid (hydrogen chloride dissolved in water) react to form zinc (II) chloride and hydrogen gas according to the equation shown below:
2 HCl (aq) + Zn (s) → ZnCl2 (aq) + H2 (g)
Explanation:


The products are on the right side of the equation. For this one it would be 2AlPO4 + 3CaSO4