1. Acids & Bases

2. Properties of Acids & Bases  Acids Aqueous solutions of acids have a sour taste Turn blue litmus paper to red React with metals to produce hydrogen gas (single replacement by more active metals) React with bases to produce salt and water Many acids are electrolytes

3.  A binary acid is an acid that contains only two different elements: hydrogen and one of the more electronegative elements

4.  An oxyacid is an acid that is a compound of hydrogen, oxygen, and a third element, usually a nonmetal

5.  Bases Aqueous solutions taste bitter Turn red litmus paper blue Dilute solutions feel slippery Bases react with acids to produce a salt and water Bases are electrolytes

6.  An Arrhenius acid is a chemical compound that increases the concentration of hydrogen ions (H + ) in aqueous solution  An Arrhenius base is a substance that increases the concentration of hydroxide ions (OH - ) in aqueous solution

7.  A strong acid is one that ionizes completely in aqueous solution Increasingly strong with increasing polarity and decreasing bond energy

8.  Acids that are weak electrolytes are also weak acids  Molecules with multiple hydrogens are not necessarily strong acids, their equilibrium may not favor the products  Organic acids contain carboxylic acid functional group (-COOH)

9.  Organic acids are generally weak acids  Many common bases contain metal cations and hydroxide ions (these are polar)  When a base completely dissociates in water to yield hydroxide ions, the solution is referred to as alkaline  Ammonia is a base because it produces hydroxide ions when it reacts with water  NH 3 + H 2 O ---> NH 4 + + OH -

10.  The strength of a base depends on the extent to which the base dissociates The alkalinity depends on the concentration of hydroxide ions in solution

12.  The Arrhenius definition of acids and bases was limited (had to be aqueous)  Bronsted and Lowry independently expanded the definition  They defined acids as proton donors and bases as proton acceptors Acid-Base Theories

13.  An acid that can donate only one proton per molecule is known as a monoprotic acid  A polyprotic acid is an acid that can donate more than one proton per molecule Sulfuric acid is know as diprotic Phosphoric acid is know as triprotic These are not necessarily stronger acids, depends on the degree of dissociation

15.  A Lewis acid is an atom, ion, or molecule that accepts an electron pair to form a covalent bond – A Lewis base donates an electron pair This is the broadest definition

17. Acid Base Reactions  The species that remains after a Bronsted-Lowry acid has given up a proton is the conjugate base of that acid (The base also produces a conjugate acid) Typically equilibrium systems with a forward and reverse reaction

18.  The stronger an acid, the weaker its conjugate base; the stronger a base, the weaker its conjugate acid  Proton-transfer reactions favor the production of the weaker acid and the weaker base

20.  Any species that can react as either an acid or a base is described as amphoteric

21.  -OH groups can be amphoteric or acidic The more polar the –OH group, the more acidic the compound The more electronegative atoms of nonmetals form acids with hydroxyl (- OH) groups Electronegative oxygens will draw the electron density away from the hydroxyl group, making it more polar

22.  In aqueous solutions, neutralization is the reaction of hydronium ions and hydroxide ions to form water molecules  A salt is also produced (an ionic compound composed of the cation from a base and the anion from an acid)