Pick up the PPT notes and the practice paper off the front

demo table.

PAP CHEMISTRY

ACIDS AND BASES

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PAP ChemChapter 1:Intro to Chem

Properties

electrolytes electrolytes

turn litmus red

sour taste

react with metals to form H2 gas

slippery feel

turn litmus blue

bitter taste

ChemASAP

vinegar, milk, soda, apples, citrus fruits

ammonia, lye, antacid, baking soda

Acids are Proton (H+ ion) Donors

Strong acids are assumed to be 100% ionized in solution (good H+ donors).

Weak acids are usually less than 5% ionized in solution (poor H+ donors).

HCl

H2SO4 HNO3

H3PO4 HC2H3O2 Organic acids

Strength

Strong Acid/Base• 100% ionized in water• strong electrolyte

- +

HClHNO3

H2SO4

HBrHIHClO4

NaOHKOHCa(OH)2

Ba(OH)2

Strength

Weak Acid/Base• does not ionize completely• weak electrolyte

- +

HFCH3COOHH3PO4

H2CO3

HCN

NH3

Acids Have a pH less than 7

Acids Taste Sour

Citric acid in citrus fruit Malic acid in sour apples Lactic acid in sour milk

and sore muscles Butyric acid in rancid

butter

Organic acids are weak acids. Some are used as flavoring agents in food.

Acids Effect

IndicatorsBlue litmus paper turns red in contact with an acid.

Methyl orange turns red with addition of an acid

Acids React with Active Metals

Acids react with active metals to form salts and hydrogen gas.

Mg + 2HCl MgCl2 + H2(g)

Zn + 2HCl ZnCl2 + H2(g)Mg + H2SO4 MgSO4 + H2(g)

Acids React with Carbonates

2HC2H3O2 + Na2CO3

2 NaC2H3O2 + H2O + CO2

Effects of Acid Rain on Marble(calcium carbonate)

George Washington:BEFORE

George Washington:AFTER

Acids Neutralize Bases

HCl + NaOH NaCl + H2O

Neutralization reactions ALWAYS produce a salt and water.

H2SO4 + 2NaOH Na2SO4 + 2H2O2HNO3 + Mg(OH)2 Mg(NO3)2 + 2H2O

OH- (hydroxide) in base combines with H+ in acids to form water

H+ + OH- H2O

Definitions

Arrhenius - In aqueous solution…

HCl + H2O H3O+ + Cl– • Acids form hydronium ions (H3O+)

H

HH H H

H

Cl ClO O–+

acid

Definitions

Arrhenius - In aqueous solution…• Bases form hydroxide ions (OH-)

NH3 + H2O NH4+ + OH-

H

H

HH H

H

N NO O–+

HH

H H

base

Definitions

Brønsted-Lowry

HCl + H2O Cl– + H3O+

• Acids are proton (H+) donors. • Bases are proton (H+) acceptors.

conjugate acidconjugate base

baseacid

Definitions

H2O + HNO3 H3O+ + NO3–

CBCAAB

Definitions

Amphoteric - can be an acid or a base.

NH3 + H2O NH4+ + OH-

CA CBB A

Definitions

F -

H2PO4-

H2O

HF

H3PO4

H3O+

Give the conjugate base for each of the following:• (these are acids)

Polyprotic - an acid with more than one H+

Definitions

Br -

HSO4-

CO32-

HBr

H2SO4

HCO3-

Give the conjugate acid for each of the following:• (these are bases-accept protons)

Definitions

Lewis• Acids are electron pair acceptors. • Bases are electron pair donors.

Lewis base

Lewis acid

Acid/Base Definitions

Type Acid BaseArrhenius H+ producer OH- producer

Bronsted-Lowry

H+ donor H+ acceptor

Lewis Electron-pair acceptor

Electron-pair donor

Anion Ending Acid Name

-ide hydro-(stem)-ic acid

-ate (stem)-ic acid

-ite (stem)-ous acid

Acid Nomenclature

HBr

H2CO3

H2SO3

• 2 elements, -ide

• 3 elements, -ate

• 3 elements, -ite

hydrobromic acid

carbonic acid

sulfurous acid

Acid Nomenclature

hydrofluoric acid

sulfuric acid

nitrous acid

• 2 elements

• 3 elements, -ic

• 3 elements, -ous

HF

H2SO4

HNO2

Acid Nomenclature

H+ F-

H+ SO42-

H+ NO2-

Properties of Bases Bases are proton (hydrogen ion, H+) acceptors

Bases have a pH greater than 7 Bases taste bitter Bases effect indicators

Red litmus turns blue Phenolphthalein turns purple

Solutions of bases feel slippery Bases neutralize acids

Bases are Proton (H+ ion) Acceptors

Sodium hydroxide (lye), NaOH Potassium hydroxide, KOH Magnesium hydroxide, Mg(OH)2

Calcium hydroxide (lime), Ca(OH)2

Bases have a

pH greater than 7

Bases Effect Indicators

Red litmus paper turns blue in contact with a base.

Phenolphthalein turns bright pink in a base.

Bases Neutralize Acids

Milk of Magnesia contains magnesium hydroxide, Mg(OH)2, which neutralizes stomach acid, HCl.

2 HCl + Mg(OH)2 MgCl2 + 2 H2O