sublimation and decoloration

Chromatography is derived from the Greek words

chroma meaning color, and graphein meaning to write. Thus, the word chromatography literally means color writing.

Sublimation

the direct conversion of a substance from solid to gas without passing through the liquid state.

Decantation

the process of separating solid-liquid components of mixtures by gently pouring out the liquid so as not to disturb the solids that readily settle at the bottom of the container.

Filtration

the process of separating the solid from the liquid by using a porous filter.

Salting-out effect

the reduced solubility in water in the presence of an electrolyte.

water

usually one of the solvents used in the extraction process

Molecular Exclusion Chromatography

(gel permeation chromatography) - liquid or gaseous phase passes through a porous gel which separates the molecules according to its size. The pores are normally small and exclude the larger solute molecules, but allow smaller molecules to enter the gel, causing them to flow through a larger volume. This causes the larger molecules to pass through the column at a faster rate than the smaller ones.

Partition Chromatography

(liquid-liquid chromatography) - uses a thin film formed on the surface of a solid support by a liquid stationary phase. Solute equilibrates between the mobile phase and the stationary liquid.

Different Classification of Chromatographic Methods

Adsorption Chromatography, Partition Chromatography, Ion Exchange Chromatography, Molecular Exclusion Chromatography, Thin Layer Chromatography, Paper Chromatography

extraction process

Gumamela = Press w/ stirring rod=Boil over low flame =filter = colored solution (extract)+ HCl + colored solution (extract) + NaOH

When can sublimation be applied as a process of separation?

It can be applied when the components of a solid mixture differ appreciably in their vapor pressures.

invented chromatography

Mikhail Semyonovich Tsvet, in 1901, while researching on plant pigments.

decolorization process of residue

Residue + water = Heat (nearly boiling)+ Activated carbon w/ stirring =Cool & filter=Filtrate - evaporate to dryness=Residue + water =+ BaCl2

two phase of chromatography

Stationary Phase and mobile phase

Stationary Phase

refers to the column packing material and is either solid or liquid. - It is usually a piece of high quality filter paper.

Mobile Phase

represents a mobile phase of liquid or gas. - The mobile phase is a developing solution that travels up the stationary phase, carrying the samples with it.

Ion Exchange Chromatography

resin (the stationary solid phase) is used to covalently attach anions or cations onto it. Solute ions of the opposite charge in the mobile liquid phase are attracted to the resin by electrostatic forces

ether

slightly soluble in water - Its efficiency can be improved by the addition of a small amount of ionizable salt, such as NaCl. - The increase polar property of the water solution will cause a decrease in the solubility of the organic solute.

Naphthalene - sodium sulfate mixture , physical appearance, polarity, type of compound and observation for residue?

sodium sulfate, powder like, non-polar, inorganic and Cloudy solution with white precipitate

Chromatography

the process of separating the substances in a complex mixture by their different affinities to the adsorbent

Diethyl ether

used extensively as an extracting solvent. - organic solvent - high solvent power for hydrocarbons and for oxygen-containing compounds. - Highly volatile. It boils at 34.60°C - Fire hazard

Extraction of water-immiscible solvent

useful for isolation of natural products that occur in animal and plant tissues that have high water content.

Adsorption Chromatography

utilizes a mobile liquid or gaseous phase that is adsorbed onto the surface of a stationary solid phase. The equilibration between the mobile and stationary phase accounts for the separation of different solutes.

EXTRACTION OF GUMAMELA FLOWERS

Extraction, by the use of solvents, is a frequently used method of withdrawing or substance from a mixture.

Thin Layer Chromatography

is usually used as an analytical technique rather than a preparative method. The stationary phase used is an adsorbent in the form of a thin layer of an inert solid on a supporting material, usually a think sheet of metal or plastic. The mobile phase is the solvent system used to separate the components of the mixture. Hexane and/or ethyl acetate is commonly used.

Naphthalene - sodium sulfate mixture , physical appearance, polarity, type of compound and observation for sublimate?

naphthalene, needle-like, non polar, organic and Colorless solution with Naphthalene crystals

sublimate

the crystals, deposit, or material obtained when a substance is sublimated.

Describe the physical properties of the sublimate collected

the crystals, deposit, or material obtained when a substance is sublimated. High vapor pressure Low melting point More volatile

residue

whatever is left after a part is taken, disposed of, or gone; remainder; rest

Paper Chromatography

a method used for testing the purity of compounds and identifying substances.

Ruhemann's Purple

a purple coloration produced by ninhydrin in the presence of an amino acid.

Technique of chromatography

Introduce a small spot of the sample on the filter paper. Put the filter paper into a container that has the mobile phase. Make sure the plate touches the mobile phase. The solvent moves up the plate due to capillary action and carries the sample upwards. Remove the filter paper and allow it to dry Spray it with ninhydrin to make the spots more visible.

How is the completeness of separation of naphthalene and Na 2 SO 4 be known with addition of BaCl 2 solution?

Naphthalene + BaCl2 → no reaction Naphthalene acid is an organic compound, while barium chloride is an inorganic compound

electrolytes

Petroleum ether Ligroin Benzene Carbon tetrachloride Chloroform Methylene chloride Ethylene dichloride N-butanol - slightly soluble in water