What equation best represents the dissociation of water moleculesinto hydrogen ions and hydroxide ions?

Answer 1

Of the three common ways of repwresenting the dissociation of water

H2O↔ H+ + OH-

2H2O ↔ (H3O)+ + OH-

H20 <-> H+aq + OH-

Number 1 is worst-- free protons are not present

Number 2 is close

Number 3 is best as it represents the fact that the proton is associated with clusters of water hydrogen bonded water molecules

Answer 2

Before an equation is shown, it's important to point out that no hydrogen ions, H+, are actually formed when water self-ionizes, or dissociates as it is often called. The positively-charged species actually formed during water self-ionization is H3O+, the hydronium ion. However, using the hydrogen ion rather than the hydronium ion in no way alters the fundamental chemical reaction in which it is used, and it makes the reaction equation simpler and cleaner. Equation 1) is the reaction normally used to represent the self-ionization of water, although it is not technically correct. Equation 2) is the true reaction for the dissociation of water. Lastly, remember that both reactions are equilibriums; meaning that the hydrogen or hydronium ions and the hydroxide ions are continuously being formed and re-combined. Also, the concentrations of the ions are very small so that the overwhelming majority of the species present is water.

Equation 1) H2O -----> H+ + OH- (In both reactions, there should be a second arrow pointing to the left to indicate that water and ions are in equilibrium.)

Equation 2) 2H2O -----> H3O+ + OH-

Answer 3

On a basic level the chemical equation is H2O → H+ + OH-

This process is called the self-ionization of water. The H2O molecule deprotonates to form the OH- ion while the H+ ion instantaneously protonates another H2O molecule to form H3O+. The equation to describe this process is H2O + H2O H3O+ + OH−

Answer 4

The equation is:

H2O------>H+ + OH-

Answer 5

H2O+H2O <---> H3O1++OH1-