Acid, Bases & Salt VideoAcid, Bases & Salt Video

Pre Test1. True

2. False

3. True

4. True

5. False

6. False

7. True

8. True

9. False

10. False

Post Test1. Neutralization

2. Base

3. Anion

4. Electrolytes

5. False

6. False

7. True

8. False

9. False

Post Test10. bitter, slippery, high

pH

11. Acids donate hydrogen, Bases accept Hydrogen

12. An easy way to gauge is something is a strong/weak acid or base

Ch. 8Solutions, Acids, & Bases

Ch. 8Solutions, Acids, & Bases

III. Particles in Solution “Like Dissolves Like” Electrolytes

A. “Like Dissolves Like”A. “Like Dissolves Like”

Polar substances will only dissolve in polar liquids• Rubbing alcohol and water

Nonpolar substances will only dissolve in nonpolar liquids• Oil and butter

Substances that aren’t the same don’t mix.• Oil and water

A. “Like Dissolves Like”A. “Like Dissolves Like”

NONPOLAR

NONPOLAR

POLAR

POLAR

Detergents• polar “head” with long nonpolar “tail”• can dissolve both types (polar and nonpolar)

B. ElectrolyteB. Electrolyte

An electrolyte is a substance that when dissolved in water form ions

Electrolytes get their name from the fact that the conduct electricity in water. Example: salt dissolved in water

Many sports drinks contain “electrolytes” which are salts dissolved in water

B. ElectrolytesB. Electrolytes

ElectrolyteNon-

Electrolytesolute exists as

ions onlyEasily conducts electricity

- +

salt

- +

sugar

solute exists asmolecules only

Does NOT conduct electricity

- +

acetic acid

WeakElectrolyte

solute exists asions and

MoleculesSlightly conducts

electricity

B. ElectrolytesB. Electrolytes

Dissociation• separation of +/-

ions when an ionic compound dissolves in water

B. ElectrolytesB. Electrolytes

Ionization• breaking apart of

polar covalent molecules into ions when dissolving in water

Ch. 8Solutions, Acids, & Bases

Ch. 8Solutions, Acids, & Bases

IV. Intro to Acids & Bases

Definitions Properties Uses

A. AcidsA. Acids

• Acids contain at least one hydrogen atom that can be removed when the acid is dissolved in water.

• These form hydronium ions, H3O+.• Also called a proton donor

HCl + H2O H3O+ + Cl–

A. BasesA. Bases

• Bases form hydroxide ions (OH-) in a water solution.

• a proton acceptor

NH3 + H2O NH4+ + OH-

A. IndicatorsA. Indicators

• Indicators are an organic substance that changes color in an acid or base.

Examples:• litmus - red/blue• phenolphthalein - colorless/pink• goldenrod - yellow/red• red cabbage juice - pink/green

B. PropertiesB. Properties

sour tastepH less than 7corrosiveelectrolytes turn litmus red react with metals to

form H2 gas

bitter tastepH greater than 7corrosiveelectrolytes turn litmus blueslippery feel

C. UsesC. Uses

H3PO4 –phosphoric acid - soft drinks, fertilizer, detergents

H2SO4 – sulfuric acid - fertilizer, car batteries

HCl – hydrochloric acid - gastric juiceHC2H3O2 – acetic acid - vinegar

C. UsesC. Uses

NaOH – sodium hydroxide -lye, drain and oven cleaner

Mg(OH)2 – magnesium hydroxide - laxative, antacid

NH3 –ammonia - cleaners, fertilizer

Ch. 8Solutions, Acids, & Bases

Ch. 8Solutions, Acids, & Bases

V. Strength of Acids & Bases Strength vs. ConcentrationStrong vs. Weak pH

A. Strength vs. ConcentrationA. Strength vs. Concentration

Strong and weak – tells how easy the acid or base dissociates in solution.

Concentration – The amount of acid or base in a solution.

It is possible to have a dilute concentration of a strong acid that would be less harmful than a concentrated weak acid.

A. Strength of Acids & BasesA. Strength of Acids & Bases

The strength of an acid or base depends on how completely a compound separates into ions when dissolved in water.

Ions can carry an electric charge so a strong acid will carry more electricity than weak acid.

B. Strong vs. WeakB. Strong vs. Weak

Strong Acid/Base• 100% ions in water• strong electrolyte• HCl, HNO3, NaOH, LiOH

Weak Acid/Base• few ions in water• weak electrolyte• HC2H3O2, NH3

- +

- +

B. Strong AcidsB. Strong Acids

Acids that ionize almost completely in a solution are strong acids.

Ex: HCl, HNO3, and H2SO4 They have a very low pH

(0-1).

B. Strong BasesB. Strong Bases

Bases that dissociate completely in a solution are strong bases.

Ex: NaOHThey have a very high pH (13-14)

C. pH ScaleC. pH Scale

0

7INCREASING

ACIDITY NEUTRALINCREASING

BASICITY

14

pH (potential of Hydrogen)• a measure of the concentration of H+

ions in a solution • measured with a pH meter or an

indicator with a wide color range (0-14)

C. pH ScaleC. pH Scale

pH of Common SubstancespH of Common Substances

Which of the following "molecular" pictures best represents a concentrated solution of the weak acid HA?

ConcepTestConcepTest

A B

Is the following statement TRUE or FALSE?• A strong acid has a lower pH than a

weak acid.• True- • But: Strong/weak refers to amount of

ionization whereas pH refers to concentration of H+.

ConcepTestConcepTest

Ch. 8Solutions, Acids, & Bases

Ch. 8Solutions, Acids, & Bases

VI. Neutralization Neutralization Reaction

A. Neutralization ReactionA. Neutralization Reaction

Chemical reaction between an acid and a base.

Products are a salt (ionic compound) and water.

ACID + BASE SALT + WATER

HCl + NaOH NaCl + H2O

Neutralization does not always mean pH = 7.

=

A. Neutralization ReactionA. Neutralization Reaction

KOH + HNO3 H2O + KNO3

Acid

Base

Salt

HNO3

KOH

KNO3

A. Neutralization ReactionA. Neutralization Reaction