Hydrogen Ions and acidity Unit 13 Chapter 19

Hydrogen Ions and acidity Unit 13 Chapter 19 -2

1 more definition of acids and bases u. Lewis acids and bases –Acid: accepts a pair of electrons –Base: donates a pair of electrons

Self-ionization u. A rxn where water molecules produce ions

Neutral Solutions u. In water the [OH-] and -7 the [H+] is 1 X 10 M…. so they are equal in concentration u. Neutral solutions contain equal amounts of OH- ions and H+ ions

Ion product u. Naturally as you inc the [H+] the [OH-] dec u. The [OH-] and [H+] has -14 to equal 1. 0 X 10 u. Kw = ion-product constant for water Kw = [H+] X [OH-] = 1. 0 X 10 -14

Acidic solutions u. Solution where the [H+] ions are larger than the [OH-] ions

Basic/ alkaline solutions u. Solution where the [H+] ions are less than the [OH-] ions.

The p. H concept u. Sorensen created the p. H scale up. H scale ranges from 014 u 7= neutral u 0 = strongly acidic u 14 = strongly basic

The p. H concept up. H is the negative logarithm of [H+]. up. H = -log[H+] up. OH = -log[OH-] u for water solutions, p. H + p. OH = 14

Acid-base indicator u. An indicator is a dye that changes a particular color depending on the acidity of the solution u. Fig 19 -12, P 602 up. H meters

Indicators important to lab Name Acid color Base color Methyl Orange Red Yellow Bromthymol blue Yellow Blue Phenolphthale Colorless in Violet Alizarin yellow Yellow Red Litmus blue Red