Neutral Water

[Leanna1H]

In neutral water, why do we always assume that [H30+]=[OH-]?

[Armaan Judge 3L]

In a solution of pure water, water molecules will exchange H+ ions with each other, albeit not to a large extent. This self-ionization is shown in the equation:

2H2O --> H3O+ + OH-

Essentially, every time a hydrogen ion is transferred from one water molecule to another, one water molecule will become an H3O+ ion, while the other will become an OH- ion. So every time, one hydronium ion is being produced and one hydroxide ion is produced, so [H3O+] will always be equal to {OH-] in pure water.

[Elise Wu 1G]

If there is an unequal concentration of hydronium (H3O+) ions and hydroxide ions (OH-), then the solution would not be neutral; it would be either acidic or basic. Acidic solutions have a greater concentration of hydronium ions while basic solutions have a higher concentration of OH- ions. When the concentration of both ions are equal, then the solution is neutral.

[mieke van daelen 2I]

The water is neutral because there is an equal amount of H3O+ and OH-. This occurs because in the reaction, each H20 becomes 1 H3O+ and 1 OH-, causing these to be present in equal levels.

[Ben Hsieh 3I]

The definition of having a neutral solution of water is that the H3O+ and OH- concentrations are the same. An alteration in the concentrations would cause the pH of the water to skew and become basic or acidic.

[Sabrina_Huang_1K]

By specifying that the water is neutral, we can assume that the concentrations of OH- and H3O+ if the water was not neutral it would be either acidic or basic which would either result in a higher H3O+ concentration or OH- concentration respectively.

[Kimberly_Wu_3H]

If water is neutral, that means that there is an equal amount of OH- and H3O+. If the water is not neutral, it would be basic or acidic, which wouldresult in a higher H3O+ or OH- concentration.

[Daniella Viorato 2G]

For the water to be considered neutral we would need equal parts [H3O+] and [OH-], similar to how we can say that Kw=1x10^-14, when divided equally in 2 to find the [ ] of H3O+ and OH-, equals 1x10^-7, because the Kw value is split equally in neutral water @25*C

[Marina Nimnual]

Neutral water means that it is neither acidic nor basic. This indicates that there are equal amounts of H3O+ and OH-. Therefore, the concentration for them must be equal to each other.

[305693278]

As, everyone else has iterated, neutral water assumes a pH of 7. Thus, with Kw = 1.0 x 10^-4, when you do pKw you get 14; pKa and pKw should add up to 14, then, since Kw = Ka x Kb. For pH and pOH to be neutral and add up to 14, the concentrations of H+ and OH- must be equal at 1.0 x 10^-7, since those are what are used to find pH and pOH (-log(H+) = pH and -log(OH-) = pOH).

[Saba Honarvar 3A]

Because neutral means that it is neither acidic or basic, the [H30+]=[OH-] would mean that the concentrations are the same and there is an equal amount of [H30+] and [OH-]. But if it was acidic or basic, the pH would be higher or lower for either one which would mean that if they are not the same concentrations, they would be acidic or basic.