AcidBase

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Acid-Base PropertiesOBJECTIVES

of

Organic Compounds

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

EXPERIMENT

5

ARMSALCEDO [email protected]

IR ANALYSIS

EXPERIMENT

5


Objectives

to describe the structural features common to compounds that belong to a specific functional grouping

to be able to differentiate each component of a given mixture of organic functionality based on solubility and acid-base properties

OBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

IR ANALYSIS

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EXPERIMENT

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Highlighted Concepts

can be determined without changing the chemical identity of a

substance

examples are physical color, odor, physical state, solubility

and density

Physical PropertiesPhysical PropertiesOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

IR ANALYSIS

EXPERIMENT

5



Acids and BasesAcids and Bases

Brönsted-LowryBrönsted-Lowry LewisLewis

AcidsAcids

BasesBases

Proton donor

Proton acceptor

Electron pair acceptor

Electron pair donor

OBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

IR ANALYSIS

3

EXPERIMENT

5



Acid-Base propertiesAcid-Base propertiesOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

AcidsAcids BasesBasessour in taste

increase H+ concentration

taste bitter and feel soapy

increase OH- concentration

“Organic acids and bases are weak in nature and don’t

ionize completely in H2O.”IR ANALYSIS

EXPERIMENT

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Acid-Base properties of organic compoundsAcid-Base properties of organic compoundsOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

organic acids and bases are weak in nature and don’t ionize

completely in H2O

organic compound’s acid – base behavior can be obtained by

solubility comparison in aqueous acids and aqueous bases

IR ANALYSIS

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EXPERIMENT

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SolubilitySolubilityOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

ability of a substance to dissolve

solute – the substance being dissolve

solvent – a substance in which other substances are

dissolved

solution – mixture of solute and solvent

maximum amount of solute that dissolves in a solvent at

equilibrium

IR ANALYSIS

EXPERIMENT

5



Factors affecting solubilityFactors affecting solubilityOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

TEMPERATURE

around 95% of solid solutes, the solubility increases with

temperature

PRESSURE

the solubility of a gas in a liquid is directly proportional to

the partial pressure of that gas above the liquid (Henry’s

Law)

POLARITY

“Like dissolves like.”

IR ANALYSIS

5

EXPERIMENT

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Solubility vs MiscibilitySolubility vs MiscibilityOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

SOLUBILITY - a measure of one substance's ability to

dissolve in a specific amount of another substance at standard

temperature and pressure

MISCIBILITY - a measure of how easily different liquids will

dissolve when mixed together

IR ANALYSIS

EXPERIMENT

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ReagentsOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Amyl acetate

Cyclohexane

EthylamineEthanol

Benzoic acidPhenol

IR ANALYSIS

Reference StandardReference Standard

6

EXPERIMENT

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ReagentsOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Hydrochloric acid (HCl)

strong acid because it can be completely dissociated with

water

Sodium hydroxide (NaOH)

strong metallic base which reacts with strong acids to form

water and its corresponding salts

Sodium bicarbonate (NaHCO3)

white crystalline solid which when treated with acids

decomposes to water and CO2

IR ANALYSIS

EXPERIMENT

5


ProcedureOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Amyl acetate

Cyclohexane

Ethylamine

Ethanol

Benzoic acid

Phenol

5 drops or

microspatula

physical state

color

odor

Physical PropertiesPhysical Properties

IR ANALYSIS

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EXPERIMENT

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ProcedureOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

1. Amyl acetate

2. Cyclhexane

3. Ethylamine

4. Ethanol

5. Benzoic acid

6. Phenol

Solubility/Miscibility TestSolubility/Miscibility Test

+ 1 mL 1M HCl

+ 1 mL 1M NaOH

Observe

and record

the

solubility of

each

compound

1 2 3 4 5 6

1 2 3 4 5 6

IR ANALYSIS

EXPERIMENT

5


ProcedureOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Benzoic acid Phenol

Solubility/Miscibility TestSolubility/Miscibility Test

Observe

and record

the

solubility of

each

compound

NaHCO3

+ 10

drops

microspatula 10 drops

Observe for any effervescence.IR ANALYSIS

8

EXPERIMENT

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ResultsOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Organic Sample

Physical Properties Miscibility

Physical State

Odor, ColorWith 1M HCl*

With 1M NaOH*

_ _ _Amyl acetate Liquid

Before heating:

After heating:

immiscible immiscibleBanana-like odor; Colorless.

Banana-like odor;

Colorless.

Cyclohexane LiquidGasoline-like odor ;

Colorless immiscible immiscible

Ethylamine LiquidAmmonia-like odor;

Colorless miscible miscible

Ethanol LiquidAlcohol-like odor;

Colorless miscible miscible

With NaHCO3*

Benzoic Acid SolidOdorless; White, fine

powder insoluble soluble

-With

effervescence

Phenol LiquidFormalin-like odor; Light

red immiscible miscible

-Without

effervescence

IR ANALYSIS

EXPERIMENT

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DiscussionOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Amyl AcetateAmyl Acetate

neutral compound

participate in H-bond as hydrogen-bond acceptors, but cannot

act as hydrogen-bond donors

ester molecules cannot hydrogen-bond to each other

immiscible in both HCl and NaOH

IR ANALYSIS

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EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

CyclohexaneCyclohexane

neutral compound

cannot form H bonds because of their non-polarity

immiscible in both HCl and NaOH

IR ANALYSIS

EXPERIMENT

5



REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

EthanolEthanol

can form H-bond

considered neutral compound but may act as acid or base

can dissolve in both polar and non-polar substances

miscible with HCl and NaOH

IR ANALYSIS

10

EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

EthylamineEthylamine

can form H-bond

act as a base

basicity depends on the availability of the lone pair of electrons

of N and on the electronic properties of the substituents

miscible with HCl and NaOH

Reaction of Ethylamine with HCl

CH3CH2NH2 + HCl � CH3CH2NH3+ + Cl-

IR ANALYSIS

EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Benzoic acidBenzoic acid

can form H-bond

act as an acid

soluble in NaOH

insoluble in HCl and forms effervescence with NaHCO3

Reaction of Benzoic acid with NaOH

C6H5COOH + NaOH � C6H5COO-Na+ + H2OIR ANALYSIS

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EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

PhenolPhenol

can form H-bond

slightly acidic

miscible in NaOH

immiscible in HCl and does not form effervescence with

NaHCO3

Reaction of Phenol with NaOH

IR ANALYSIS

EXPERIMENT

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Infrared AnalysisOBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

EthylacetateEthylacetate

IR ANALYSIS

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EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

CyclohexaneCyclohexane

IR ANALYSIS

EXPERIMENT

5



REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

EthylamineEthylamine

IR ANALYSIS

13

EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

EthanolEthanol

IR ANALYSIS

EXPERIMENT

5



REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

Benzoic acidBenzoic acid

IR ANALYSIS

14

EXPERIMENT

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REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

PhenolPhenol

IR ANALYSIS

EXPERIMENT

5


OBJECTIVES

REAGENTS

PROCEDURE

RESULTS

CONCEPTS

DISCUSSION

IR ANALYSIS

PREPARED BY:PREPARED BY:PREPARED BY:PREPARED BY:

[email protected]

AcidBase

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