Important Definitions

Acid- means "sour"- a compound that can donate a proton.
Base- a compound that can accept a proton. An example of a base is sodium hyrdoxide.
Binary acid- an acid that contains only two different elements, hydrogen and another element.
Oxyacid- an acid that is made up of oxygen, hydrogen, and another element which is usually a nonmetal.

Properties of Acids:
  • Aqueous solution of acids have a sour taste to them.
  • Acids can chage the color of Acid/base indicators. When pH paper is used as the indicator, it turns a certain color in acidic solutions.
  • Acids with active metals sometimes release a hygrogen gas.
  • Acids react with bases and create water and salts.
  • Acids can cunduct electricity.


Common Binary Acids
Formula
Acid Name
HF
Hydrofluoric acid
HCl
Hydrochloric acid
HBr
Hydrobromic acid
HI
Hydriodic acid
H2S
Hydrosulfuric acid

Common Oxyacids Names
Formula
Acid Name
HIO3
Iodic Acid
HClO
Hypochlorous Acid
HNO2
Nitrous Acid
H3PO3
Phosphorous Acid
H2SO3
Sulfurous Acid

Common Acids

Sulfuric Acid- It is the most commonly produced acid in the world, and is used in products like car batteries, metals, paper, paint, dyes, detergents, and raw chemical materials. This acid also attracts water which makes it good for dehydrating products.
Nitric Acid- Nitric acid in its pure form is very unstable.When dissolved in water the acid becomes stable, and can be used in rubber, plastics, dyes, and pharmaceuticals.
Phosphoric Acid- Phosphoric acid is an essential element for plants and animals. The majority of it that is produced each year is used for fertilizers and animal feed. Diluted phosphoric acid is used as a flavoring agent in beverages and as a cleaning agent for dairy equipment. It is an important part in manufacturing detergents and ceramics.
Hyrdochloric Acid- Hyrdochloric acid is important for pickling (the immersion of metals in acid solutions to remove surface impurities) iron and steel. It is used in the activation of oil wells, the recovery of magnesium from sea water, and in the production of other chemicals.
Acetic Acid- Acetic acid is impotant in synthesizing chemicals used in the manufacture of plastics. It is a raw material in the production of food supplements, and is also sed in fungicide.

Arrhenius Acids and Bases

Arrhenius acids and bases were named after Svante Arrhenius, a Swedish chemist who lived from 1859-1927, and understood that aqueous solutions of acids and bases conducted electric current; he theorized that acids and bases must produce ions in solutions. An Arrhenius acid is a chemical compound that increases the concentration of hydrogen ions in aqueous solutions. An Arrhenius base is a substance that increases the concentration of hyrdoxide ions in aqueous solutions.

Strength of Acids

A strong acid is an acid that ionizes completely in aqueous solutions and is a strong electrolyte. The strength of an acid depends on the polarity of the bond between hyrdogen and the element to which it's bonded and the ease with which that bond can be broken. A weak acid is an acid that releases few hyrdogen ions in aqueous solutions. A weak acid is generally an acid that contains the acidic carboxyl group (COOH); an example of one is CH3COOH.

Aqueous Solutions of Bases

Most bases are ionic compounds that contain metal cations and the hyrdoxide anion, OH-. Since these bases are ionic, they disocate when dissolved in water. If a base completely dissociates in water to yield aqueous OH- ions, the solution is referred to as strongly basic. But not all bases are ionic compounds. An example of a base that is not an ionic compound is a ammonia NH3, which is molecular; it is a base because it produces hyrdoxide ions when it reacts with water molecules.

Strength of Bases

The strength of bases depends on the extent to which the base dissociates. A strong base is one that is a strong electrolyte. A weak base is a base that is a weak electrolyte. An example of a strong base is RbOH because it completely dissociates into its ions in dilute aqueous solutions. An example of a weak base is NH3 because it is a weak electrolyte. Many organic compounds that contain nitrogen atoms are weak bases.

Bronsted-Lowry Acids and Bases

Bronsted-Lowry acids and bases were named after the Danish chemist J.N. Bronstred and the English chemist T.M. Lowry who independently expanded the Arrhenius acid and base definition. A Bronsted-Lowry acid is a molecule or ion that is a proton donor. A Bronsted-Lowry base is a molecule or ion that is a proton accetor. In a Bronsted-Lowry acid-base reaction protons are tranferred from the acid to the base.

Monoprotic and Polyprotic Acids

A monoprotic acid is an acid that can donate only one proton (hyrdogen ion) per molecule. Examples of monoprotic acids are perchloric acid, hyrdochloric acid, and nitric acid. A polyprotic acid is an acid that can donte more than one proton per molecule. Examples of polyprotic acids are sulfuric acid and phosphoric acid. Sulfuric acid is a type of polyprotic acid that can donate 2 protons per molecule, it is known as a diprotic acid. Phosporic acid is a type of polyprotic acid that is able to donate 3 protons per molecule, it is called a triprotic acid.

Lewis Acids and Bases

A Lewis acid is an atom, ion, or molecule that accepts an electron pair to form a covalent bond. A Lewis Base is an atom, ion, or molecule that donates an electron pair to form a covalent bond. A Lewis acid-base reaction is the formation of one or more covalent bonds between an elctron-pair donor and an elctron-pair acceptor.

Conjugate Acids and Bases

A conjugate base is what remains of an aicd after it has given up a proton. A conjugate acid is what remains of a base after it has accepted a proton.

How to determine the acid and the base in a reaction

HCl + H2O--> H3O + Cl

The HCl lost its hydrogen proton, therefore it is an acid. The H2O gains a proton, which makes it the base.
H30 is the conjugate acid of the base H2O compound. Cl is the conjugate base of the acid HCl.

Strong Acid-Strong Base Neutralization

Neutralization is the reaction of hydronium ions and hyrdoxide ions to form water molecules. An acid-base reaction occurs in aqueous solutions between a strong acid that cmpletely ionizes to produce a strong base that completely dissociates to produce OH-. An example of this is:
H3O-(aq) + Cl-(aq) + Na+(aq) + OH-(aq) ---> Na+(aq) + Cl(aq) + 2H2O(l)
Water is not the only product of neutralization, salt is also a product because salt is an ionic compound composed of a cation from a base and an anion from an acid.

Acid Rain

Acid Rain is very acidic rainwater. It can erode statues and affects ecosystems, such as water enviroments and forests.
acid_rain_forest.jpg
This is a forest that has been damaged by acid rain. http://www.encarta.msn.com
Acid_rain.jpg
Notice the difference between the branch on the right, which has been damaged by acid rain, and the branch on the left, which has not been damaged by acid rain. http://www.media-2.web.britannica.com



Information from Modern Chemistry by Holt, Rinehart, and Winston.