Chem 20 AP acids and bases

Neutralization is defined as the reaction between a hydronium ion and a hydroxide ion to produce water. 

(H30+ (aq) + OH- (aq) ------> 2H20 (l))

the core of the ion (1 singular proton and neutron)

• Base= accept H+
• Acid= donate H+

According to the modified arrhenius theory, acids are substances that reacts with water to produces hydronium ions (H3O+). Meanwhile, bases are substances that dissociate or react wih water to produce hydroxide ions.

the modified arrhenius theory better explains the acidic and basic properties of substances that the original theory could not explain. This theory is still limited in that it can only describe acid-base chemistry in aqueous solutions and it does not always allow you to predict whetehr a substance will be an acid or a base.

Look for an ionic compound where hydroxide is the anion. The rules for naming and writing formulas for bases are the same as the rules for ionic compounds.

classical acid name: ___ous acid

IUPAC acid name: aqueous hydrogen ____ite

Classical acid name: ___ic acid

IUPAC acid name: aqueous hydrogen ___ate

Classical acid name: hydro____ic acid

IUPAC Acid name: aqueous hydrogen ____ide

When acids are dissolved in water, they are given an acid name and their state of matter becomes aqueous to indicate that it is dissolved in water.

Follow the same rules as naming and writing formulas of ionic compounds.

A carboxylic acid.

To recognize an acid from the chemical formula, look for the hydrogen symbol on the left paired with an anion on the right (HA) or (something)-COOH on the right.

Empirical definition: Neutral substances form solutions that do not affect litmus. Some are electrolytes while others are not. (Ex. some are molecular compounds, making them non electrolytic. Additionally, some ionic compounds do not dissociate, making them non electrolytic aswell.)

Arrhenius's theory: No H+ (aq) or OH- (aq) ions are formed. Some are ions in solution while some are molecules in solution.

Empirical definition: Bases form solutions that turn red litmus blue and are electrolytes. They also neutralize acids.

Arrhenius theory: Ionic hydroxides dissoicate to produce OH- (aq) ions. OH- (aq) ions reacts with H+ (aq) ions to produce water.

Empirical definition: Acids form solutions that turn blue litmus red and are electrolytes. They also neutralize bases. 

Arrhenius theory: some hydrogen compounds ionize to produce H+ (aq) ions. H+ (aq) ions react with OH- (aq) ions to produce water.

The pOH scale is used to communicate a broad range of hydroxide ion concentrations. Each change of one pOH unit corresponds with a change in the hydroxide ion cocnentration of 10x.

(both hydroniums and hydroxides are always present, however when one goes up the other goes down, just like a scale.)

Polyprotic bases react more than once with water to produce hydroxide ions. For molecular bases, the reaction with water is less complete with each successive step (each time it reacts, the reaction is more and more incomplete). generally, the number of times an ion can act as a base is the same as the negative charge on the ion. (ex. PO4 3- can react with water 3 times.)

Monoprotic bases dissociate or react with water only once to produce hydroxide ions. Ex. ammonia.

Polyprotic acids contain more than one acidic hydrogen atom in their compound formula and can react with water more than once to produce hydronium ions. 

Diprotic acids contains 2 hydrogen atoms that can react with water

Triprotic acids contain 3 hydrogen atoms that can react with water. 

In general polyprotic acids are weak acids (except for sulfuric acid which is strong) whose reaction with water decreases with each successive step (reacts with water more incompletely everytime it reacts with water)

Monoprotic acids have only one acidic hydrogen atom (one proton to donate) in their compound formula and can only react once with water to produce hydronium ions. Strong acids (except sulfuric acid) and many weak acids are monoprotic.

A weak base reacts or dissociates partially (<50%) with water too produce relativley few hydroxide ions. This results in a solution with weak basic properties and a pH closer to 7. Most bases, other than ionic hydroxides of group 1 and 2 (except beryllium) or oxides of group 1 and 2 (beryllium) are weak bases. An equillibrium arrow (double arrows) is used in the chemical reaction equation. The major entities present in water will be the reactant and water.

A strong base dissociates completely in water to produce hydroxide ions. This results in a solution with strong basic properties and a high pH. All ionic hydroxides of groups 1 and 2 (excpet beryllium) are strong bases. All oxides of groups 1 and 2 (except beryllium) are strong bases because they react with water to procue an ionic hydroxide. A single directional arrow (quantitative arrow) is used in the chemical reaction equation. The major entities present in water wll be the products and water.

Weak acids react imcompletely with water (less than 50%) to produce relativley few hydronium ions. The relativley low concentration of hydronium ions results in weaker acid properites and a pH closer to 7. The reason lower hydronium concentrations are produced is because when there is a weak acid, technically water is a stronger acid and since acids have a tendency to donate hydrogens and not accept them, water has a harder time accepting hydrogens from a weak acid in comparison to a strong acid, resulting in a low hydronium concentration when there is a weak acid. The major entities present in solution are the reactants. An equilibrium arrow (double arrows) is used in the chemical reaction equation. The extent of the reaction can be written above the arrow.

Strong acids react completely (more than 99%) with water to produce hydronium ions. The high concentration of hydronium ions resuls in strong acid properties and a low pH. The major entities present in solution are the products and water. A single directional arrow is used in the chemical reaction equation (quantitative arrow). >99% can be written above the arrow.

Purple cabbage juice

pH paper contains several different indicators and shows different colors at different pH values. 

pH meters are used to provide a precise measure of the pH of a solution

Acid-base indicatord are substances that change color when the acidity of the solution changes.

pOH (power of hydroxide) of a solution is a measure of the hydroxide ion concentration, or alkalinity, of a substance

Ex. a hydroxide ion concentration of 1x10^-2 mol/L corresponds with a pOH of 2.

the pH scale is used to communicate a broad range of hydronium ion concentrations. Each change of one pH unit corresponds with a change in the hydronium concentration of 10x. (log based scale)

Ex. pH of 1= 10^-1 mol/L of hydronium ions while pH of 2= 10^-2 mol/L of hydronium ions

The pH (power of hydrogen) of a solution is a measure of the hydronium ion concentration, or acidity, of a substance.

pH=1

Neutral solutions: [H30+(aq)] = 1x10^-7 mol/L and [OH- (aq)] = 1x10^-7 mol/L and pH=7

Acidic solutions: [H30+ (aq)] > 1x10^-7 mol/L and [OH- (aq)] < 1x10^-7 mol/L and pH<7

Basic solutions: [H30+ (aq)] < 1x10^-7 mol/L and [OH- (aq)] > 1x10^-7 mol/L and pH>7

Arrhenius's theory of solutions accounts for many of the empricial properties of different subsances in solution.