Acids and Bases

Lewis Theory
1. acids are electron pair acceptors
2. bases are electron pair donors
pH
14 – pOH
-log([OH-])
pOH
14 – pH
-log([H+])
[H+]
2nd log(-pH)
[OH-]
2nd log(-pOH)
pH Scale
– 7 is neutral
– below 7 is acidic, acids that are lower on the scale (1-3) are strong acids, 4-6 are weak acids
– above 7 is basic, bases that are higher on the scale (11-14) are strong bases, 8-10 are weak bases
pOH Scale
– 7 is neutral
– below 7 is basic, bases that are lower on the scale (1-3) are strong bases, 4-6 are weak bases
– above 7 is acidic, bases that are higher on the scale (11-14) are strong acids, 8-10 are weak acids
Conjugate Acid
substance created after a base receives a proton (H+)
Conjugate Base
substance left over after an acid loses it’s proton (H+)
Alkalis
bases that dissolve in water
Bases (in relation to alkalis)
bases that do not dissolve in water bases
*note that all alkalis are bases, but not all bases are alkalis*
Concentration
the amount of the acid or base per unit volume (liter)
Strength
the acid is dependent on the concentration of hydrogen ions, the ability of the acid to lose hydrogen ions, and therefore it’s also able to lose it’s concentration of hydrogen ions
– a strong acid dissociates completely to form hydrogen ions
– a weak acid dissociates partially to form hydrogen acid
4 Neutralization Reactions
acid + base –> salt + water
acids + metal –> salt + hydrogen gas
acid + carbonate –> salt + water + CO2
acid + alkali –> salt + water
Making Salts
acid + base –> neutralization
– four ways that you can neutralize
– every time a neutralization occurs a salt is formed (this salt is neutral)

Families of Salts
– “the chlorides” –> hydrochloric acid makes a chloride salt
– “the sulfates” –> sulfuric acid makes a sulfate salt
– “the nirtrates” –> nitric acid makes a nitrate salt
– these are large groups of salt compounds
the compound that is produced is dependent on the acids you use

Molarity of Acids and Bases
*if you are given the molarity of an acid, the molarity is the concentration, and the concentration is the measure of the [H+]*
BUT *if you are given the molarity of a base, the molarity is the concentration, and the concentration is the measure of the [OH-]*
Red and Blue Litmus Paper
bases turn red litmus paper blue (acidic and neutral solutions do not change the color of the litmus paper)

acids turn blue litmus paper red (basic and neutral solutions do not change the color of the litmus paper)

both are helpful to determine whether or not an unknown solution is either an acid or a base

Litmus Paper
able to turn a certain color depending on the solution, and you are able to associate the color it turns with a certain pH number
– maroon to red is a strong acid with a pH ranging from 1-3
– orange to lime is a weak acid with a pH ranging from 4-6
– green is a neutral solution with a pH of 7
– light blue to light purple is a weak base with a pH ranging from 8-10
– any kind of dark blue or purple is a strong base with a pH ranging from 11-14

helpful to identify an unknown solutions acidity or alkalinity as well as it’s pH number

uses of acids
– vinegar: used for cooking, contains 3-6% acetic acid –> used in pickles and in many food preparations
– lemon and orange juice: citric acid –> used in the preparation of effervescent salts as well as a food preservative
– uses in industry, nitric acid and sulphuric acid: used in the manufacture of fertilizers, dyes, paints, drugs and explosives
– sulphuric acid: used in batteries, used mostly for cars and other vehicles
– tannic acid: used in the manufacturing of ink and leather
– hydrochloric acid: used to make aqua regis –> dissolves noble metals such as gold and platinum
– sulphuric acid: used in manufacturing fertilizers such as super phosphate and ammonium sulphate
uses of bases
– sodium hydroxide (caustic soda): used in the manufacturing of soap –> used in petroleum-refining, the making medicines, paper and pulp.
– calcium hydroxide (slaked lime): used for many purposes –> to neutralize acid in water supplies, the making of bleaching powder, a dressing material for acid burns, an antidote for food poisoning and in the mixture of whitewash; mixed with sand and water to make mortar –> used in the construction of buildings and by farmers to neutralize the harmful effects of acid rain
– ammonium hydroxide: used to remove ink stains from clothes and to remove grease from window-panes, mostly used for the cosmetic industry
– alkalis: used in alkaline batteries, generally potassium hydroxide is used in such batteries
properties of acids
– tastes sour
– pH below 7
– turns blue litmus paper red
– acids neutralize bases to create salt and water
– corrosive, acids react with metals to yield salt and hydrogen gas
– acids are electrolytes
– neutralized by carbonates
– acids react with alkalis to yield salt and water
properties of bases
– taste bitter
– pH greater than 7
– turns red litmus paper blue
– bases neutralize acids to form salt and water
– conduct electricity
– slippery
– corrosive
– bases neutralize acids
Arrhenius Theory
1. when an acid dissolves in water, it produces an H+ ion
2. when a base dissolves in water, it produces H- ions
Bronsted-Lowry Theory
1. acids are proton donors
2. bases are proton acceptors

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