Acids, Bases and Salts

Acids
*Key Concept: Acids taste sour, will change the color of an acid-base indicator, and can be a strong or weak electrolyte in aqueous solutions*
Bases
*Key Concepts: Bases taste bitter, feel slippery, will change the colour of an acid-base indicator, and can be a strong or weak electrolyte*
Arrhenius Acids and Bases
*Key Concept: Arhenius said that acids are hydrogen containing compounds that ionize to yield hydrogen ions in an aqueous solution. He also said that bases are compounds that oxidize to yield hydroxide ions in an aqueous solution.*
Monoprotic acids
Acids which contain one ionizable hydrogen. Ex: Nitric Acid (HNO3)
Diprotic Acids
Acids that contain two ionizable hydrogens Ex: sulphuric acid (H2SO4)
Triprotic Acid
Acids that contain three ionizable hydrogens. Ex: Phosphoric Acid (H3PO4)
Bronsted-Lowry Acids and Bases
*Key Concept: The Bronsted- Lowry theory defines an acid as a hydrogen ion donor and a base as a hydrogen-ion accepter.*
Conjugate Acid
The particle formed when a base gains a hydrogen ion.
Conjugate Base
The particle that remains when an acid has donated a hydrogen ion
Conjugate Acid-Base Pair
Two substances related by the loss or gain of a single hydrogen ion.
Hydronium Ion
A water molecule that gains a hydrogen ion (becomes positively charged)
Amphoteric
A substance that can act as both an acid and a base.
Lewis Acids and Bases
*Key Concept: Lewis Proposed that an acid accepts a pair of electrons during a reaction while a base donates a pair of electrons.
Lewis Acid
A substance that can accept a pair of electrons to form a covalent bond.
Lewis Base
A substance that can donate a pair of electrons to form a covalent bond.
Self- Ionization
The reaction in which water molecules produce the ions H+ and OH-.
Neutral Solution
Any aqueous solution in which the [H+] and [OH-] are equal.
Ion Product Constant for Water
*Key Concept: For aqueous solutions, the product of the hydrogen-ion concentration equals 1.0×10^-14 (Kw)
Acidic Solution
One in which [H+] is greater than [OH-]
Basic Solution
One in which [H+] is less than [OH-]
Alkaline Solution
Another name for a basic solution.
pH
the solution of the negative logarithm of the hydrogen-ion concentration. *Key Concept: In a solution in which [H+] is greater than 1×10^-7 M has a pH less than 7 and is an acid. The pH of pure water or a neutral aqueous solution is 7.0. A solution with a pH greater thab 7 is basic nd has [H+] of less than 1.0×10^-7
pH=-log[H+]
Acid-Base Indicaor
*Key Concept: An indicator is a valuable tool for measuring pH because its acid form and base form have different colours in the solution
Strong Acid
Completely ionize in an aqueous solution.
Weak acids
Ionize only slightly in aqueous solutions.
Acid Dissociation Constant
The ratio of the concentration of the dissociated form of an acid to the concentration of the undissociated form. *Key Concept: Weak Acids have small Ka Values. The stronger an acid, the larder its Ka value.*
Strong Base
Dissociate completely into metal ions and hydroxide ions.
Weak Base
Reacts with water to form the hydroxide ions and the conjugate acid of the base.
Base Dissociation Constant
(Kb) The ratio of the concentration of the conjugate acid times the concentration of the hydroxide ions to the concentration of the base.
Calculating Dissociation Constants
*Key Concept: To find Ka of a weak acid or the Kb of a weak base, substitute the measured concentrations of all the substances present at equilibrium into the expression for Ka and Kb.*
Neutralization Reaction
A reaction in which an acid and a base react in an aqueous solution to form a salt and water. *Key Concept: In general, the reaction of an acid with a base produces water and one of a class of compounds called salts.*
Equivalence Point
When an acid and base are mixed, it is when the number of moles of hydrogen ions equals the number of moles of hydroxide ions.
Titration
The process of adding a known concentration to determine the concentration of another solution.
Standard Solution
The solution of known concentration in a titration reaction.
End Point
The point at which the indicator changes colour in a titration. *Key Concept: The point of neutralization is the endpoint of the titration.*