Separation of Acid, Base and Neutral Compounds from a Solid Mixture by Liquid-Liquid Extraction

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Experiment #1: Separation of Acid, Base, and Neutral Compounds from a Solid Mixture by Liquid-Liquid Extraction

Introduction

Liquid-liquid extraction is a technique used to separate chemical substances in order to purify or identify the various components of a mixture. Flavors, spices, perfumes, and medicines are just some of the everyday things that are extracted from plants and other natural sources [1]. The basic principle used to carry out this separation is the mixing of two liquids that are immiscible with each other. This creates layers of liquid, which can be separated and then isolated to help to identify compounds. Another important concept to remember in this experiment is that ionic salts are polar and therefore water
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The solution was completely evaporated after 3 minutes.

15 NaOH pellets were added to the salt of the base and pH paper was red (acidic), with no precipitate. 5 more pellets added and the pH paper turned blue (basic), but there was still no precipitate. With the salt of the acid, 2 full disposable pipette amounts of HCl were added and the pH paper turned blue (basic), with no precipitate. Another 1.5 pipettes added and an immediate white powdery precipitate observed. The pH then tested as acidic.

Unknown 306 – 1.02g Salicylic Acid Naphthalene
Obtained Melting Point 154°C - 158°C 76°C - 79°C
Amount Recovered .52g .45g
% Yield 101.96% 88.24%
Physical White solid, fine granules White solid, crystals
Figure 1.0

Sample Calculations:

Amount of salicylic acid recovered:

Final Round Bottom Flask Weight: 47.50g - Initial Round Bottom Flask Weight: 47.05g .45g salicylic acid

Amount of naphthalene recovered:

Final Watchglass Weight: 21.95g -Initial Watchglass Weight: 21.43g .52g naphthalene

The starting unknown weight was 1.02g; therefore, the maximum yield is .51g of each component, if the unknown was a 50/50 mixture.
% Yield of salicylic acid:

Actual = .52g x 100 = 101.96% yield salicylic acid Theoretical .51g

% Yield of naphthalene:

Actual = .45g x 100 = 88.24% yield naphthalene Theoretical .51g

Discussion

The procedure of this

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