Relationship With The Neutral Point of Water
Water molecules dissociate into equal amounts of H3O+ and OH−, so their concentrations are equal to 1.00 × 10−7 mol∙dm−3 at 25 °C. A solution in which the H3O+ and OH− concentrations equal each other is considered a neutral solution. In general, the pH of the neutral point is numerically equal to pKw/2.
Pure water is neutral, but most water samples contain impurities. If an impurity is an acid or base this will affect the concentrations of hydronium ion and hydoxide ion. Water samples which are exposed to air will absorb the acid carbon dioxide and the concentration of H3O+ will increase. The concentration of OH− will decrease in such a way that the product remains constant for fixed temperature and pressure.
Read more about this topic: Self-ionization Of Water
Famous quotes containing the words relationship, neutral, point and/or water:
“Some [adolescent] girls are depressed because they have lost their warm, open relationship with their parents. They have loved and been loved by people whom they now must betray to fit into peer culture. Furthermore, they are discouraged by peers from expressing sadness at the loss of family relationships—even to say they are sad is to admit weakness and dependency.”
—Mary Pipher (20th century)
“The United States must be neutral in fact as well as in name.... We must be impartial in thought as well as in action ... a nation that neither sits in judgment upon others nor is disturbed in her own counsels and which keeps herself fit and free to do what is honest and disinterested and truly serviceable for the peace of the world.”
—Woodrow Wilson (1856–1924)
“Sleaze is a point by point refutation of elegance.”
—Mason Cooley (b. 1927)
“Cities give not the human senses room enough. We go out daily and nightly to feed the eyes on the horizon, and require so much scope, just as we need water for our bath.”
—Ralph Waldo Emerson (1803–1882)