acid/base or chemical extraction

what reagent is added to the test tubes to produce the solid?

HCl

what is the drying agent for this lab?

MgSO₄

what reagent reacts with benzoic acid?

NaHCO₃

what reagent reacts with 2-napthol?

NaOH

what is the pKa of 2-naphthol?

-10

what is the IR peak for C=O bonds?

-1700 cm⁻1

what is the IR peak for C-H bonds?

-3000 cm⁻1

what is the IR peak for O-H bonds?

-3300 to 3600 cm⁻1

what is the pKa of benzoic acid?

-4.1

other common drying agents?

-CaCl₂ -CaSO₄ -MgSO₄ -K₂CO₃ -Na₂SO₄

what should be added to test tubes B and C to form benzoic acid and 2-naphthol?

-HCl

emulsion

-a drop or suspension of liquid in another -they are very stable once they are formed -countered by stirring/mixing well and vacuum filtration/centrifugation

what do drying agents do?

-absorb or remove water

what is an example of liquid drying agent?

-aqueous NaCl pull water into the aqueous layer

what is backwashing?

-backwash with ether to remove and organic components from the test tubes

what is the conjugate base of benzoic acid?

-benzoate -same structure but with hydrogen proton removed

what is in the ternary mixture?

-benzoic acid -2-napthol -1,4-dimethoxybenzene

intermolecular forces for 2-naphthol?

-can hydrogen bond in water -polar

intermolecular forces for benzoic acid?

-can hydrogen bond to water -polar

what are the three functional group from this experiment?

-carboxyl group -phenol -ether

the aqueous layer

-contains the organic impurities

what is the ternary mixture dissolved in?

-diethyl ether -test tube A

inter molecular forces for 1,4-dimethoxybenzene?

-dipole dipole attractions -polar

why do you have to vent the separatory funnel?

-gas is produced during the reaction which will cause a pressure buildup

what kind of filtration is used for test tube A, 1,4-dimeothoxybenzene?

-gravity filtration

extraction

-isolation technique based on the solubility of various components in solvent(s)

what are the three types of extraction?

-liquid/solid: for example, the extraction of a flavor and odor from dried veggies (tea) -liquid/liquid: where the two liquids react, the reaction goes to completion, and creates to distinct layers -acid/base: performing a series of acid/base reactions to yield a strong acid, weak acid, and a neutral compound (can also be done to produce bases)

magnesium sulfate

-molar mass: 120.36 g/mol

benzoic acid

-molar mass: 122.12 g/mol -melting point: 122.4 C

1,4 dimethoxybenzene

-molar mass: 136.16 g/mol -melting point: 54-56 C

2-naphthol

-molar mass: 144.17 g/mol -melting point: 122 C

hydrochloric acid

-molar mass: 36.46 g/mol

sodium hydroxide

-molar mass: 39.99 g/mol

sodium bicarbonate

-molar mass: 84.00 g/mol

what is the conjugate base of 2-naphthol?

-naphthalen-2-olate -same structure with hydrogen proton removed and negative charge on oxygen

ionizable proton?

-on 2-naphthol and benzoic acid -meaning there is a proton that can be ionized -their conjugate bases have a negative charge on the oxygen, meaning they will be more soluble in water

properties of a good extraction solvent?

-same properties as a recrystallization solvent -should consider its solubility in relation to other components -should consider its reactivity in relation to other elements -should easily dissolve compound to be extracted -low boiling point -should NOT react w/solute or other solvents -inexpensive -NOT flammable or toxic -NOT miscible in water -need to know the solubility to know which layer comes out on top

what goes in test tube C after sodium hydroxide is added?

-the aqueous layer is removed and put into test tube -test tube C contains naphthalen-2-olate

what goes on test tube B after sodium bicarbonate is added?

-the aqueous layer is removed and put into test tube B -test tube b contains the sodium benzoate

what remains in test tube A after sodium bucarnonate and sodium hydroxide were aded and the aqueous layers removed?

-the neutral, organic layer -test tube A contains 1,4-dimethoxybenzene

what are the two layers produced in liquid/liquid extraction?

-the organic/ether layer and the aqueous layer

the organic/ether layer

-this layer contain the organic component, will not be soluble in water and will separate itself from the aqueous layer, it is less dense and will rise to the top

what type of filtration is used for test tubes B and C, benzoic acid and 2-naphthol?

-vacuum filtration

diethyl ether

-very strong odor -very flammable -hard to extract

diethyl ether

molar mass: 74.12 g/mol