ACIDSACIDS ANDAND BASES BASESACIDSACIDS ANDAND BASES BASES

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PropertiesProperties

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) DonorsAcids 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 HC2H3O2Organic acids

Acids Acids Have a Have a pH less pH less than 7than 7

Acids Acids Have a Have a pH less pH less than 7than 7

Acids Taste SourAcids Taste SourAcids Taste SourAcids Taste Sour

Citric acid in citrus fruitCitric acid in citrus fruit Malic acid in sour applesMalic acid in sour apples Lactic acid in sour milk and Lactic acid in sour milk and

sore musclessore muscles

Butyric acid in rancid butterButyric acid in rancid butter

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

Acids Acids Effect Effect

IndicatorsIndicators

Acids Acids Effect Effect

IndicatorsIndicators

Blue litmus paper turns red in contact with an acid.

Methyl orange turns red with addition of an acid

Acids React with Active MetalsAcids React with Active MetalsAcids React with Active MetalsAcids React with Active Metals

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

Mg + 2HCl MgCl2 + H2(g)Zn + 2HCl ZnCl2 + H2(g)

Mg + H2SO4 MgSO4 + H2(g)

Acids Acids React withReact with CarbonatesCarbonatesAcids Acids React withReact with CarbonatesCarbonates

2HC2H3O2 + Na2CO3

2 NaC2H3O2 + H2O + CO2

Effects of Acid Rain on MarbleEffects of Acid Rain on Marble((calcium carbonate)calcium carbonate)

Effects of Acid Rain on MarbleEffects of Acid Rain on Marble((calcium carbonate)calcium carbonate)

George Washington:BEFORE

George Washington:AFTER

Acids Neutralize BasesAcids Neutralize BasesAcids Neutralize BasesAcids 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

HH++ ++ OHOH-- HH22OO

DefinitionsDefinitions

Brønsted-LowryBrønsted-Lowry

HCl + H2O Cl– + H3O+

•AcidsAcids are proton (H+) donors.

•BasesBases are proton (H+) acceptors.

conjugate acidconjugate base

baseacid

DefinitionsDefinitions

H2O + HNO3 H3O+ + NO3–

CBCAAB

DefinitionsDefinitions

Amphoteric - can be an acid or a base. - can be an acid or a base.

NH3 + H2O NH4+ + OH-

CA CBB A

DefinitionsDefinitions

F -

H2PO4-

H2O

HF

H3PO4

H3O+

Give the conjugate base for each of the following:

• (these are acids)

DefinitionsDefinitions

Br -

HSO4-

CO32-

HBr

H2SO4

HCO3-

Give the conjugate acid for each of the following:

• (these are bases-accept protons)

Acid/Base DefinitionsAcid/Base Definitions

TypeType AcidAcid BaseBase

Bronsted-Lowry

H+ donor H+ acceptor

Properties of BasesProperties of BasesProperties of BasesProperties of Bases

Bases are proton (hydrogen ion, H+) acceptors Bases have a pH greater than 7 Bases taste bitter Effects on indicators-

Red litmus turns blue Phenolphthalein turns purple

Solutions of bases feel slippery Bases neutralize acids

Bases are Proton (HBases are Proton (H++ ion) ion) AcceptorsAcceptors

Bases are Proton (HBases are Proton (H++ ion) ion) AcceptorsAcceptors

Sodium hydroxide (Sodium hydroxide (lyelye),), NaOHNaOH Potassium hydroxide, Potassium hydroxide, KOHKOH Magnesium hydroxide,Magnesium hydroxide, Mg(OH)Mg(OH)22

Calcium hydroxide (Calcium hydroxide (limelime),), Ca(OH)Ca(OH)22

Bases Bases have a have a

pH pH greater greater than 7than 7

Bases Bases have a have a

pH pH greater greater than 7than 7

Bases Effect Bases Effect IndicatorsIndicators

Bases Effect Bases Effect IndicatorsIndicators

Red litmus paper turns blue in contact with a base.

Phenolphthalein turns bright pink in a base.

Bases Neutralize Bases Neutralize AcidsAcids

Bases Neutralize Bases Neutralize AcidsAcids

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

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