chemlab

organic compounds

• Characterized by the presence of carbon atoms in them

• Consists of hydrogen, oxygen, carbon, and their other derivatives

• More volatile and also highly inflammable

• Exist in the form of solids, gases, and liquids

• Insoluble in water

• Carbon-hydrogen bonds

inorganic compounds

-          do not have carbon atoms in them (some exceptions do exist)

-          Do not possess hydrogen or oxygen and their derivatives

-          Flammable and non-volatile in nature

-          Exists as solids

-          Soluble in water and non-soluble in some of the organic solutions

-          Do not have carbon-hydrogen bonds

solution

• a mixture of two or more substances that is identical throughout (homogeneous)

-          can be physically separated

-          composed of solutes and solvents

solutes

The substance that is dissolved. It is the lesser constituent by volume.

solvents

The substance that does the dissolving. It is the greater constituent by volume.

miscible

liquids can easily dissolve in one another.

immiscible

liquids that are not soluble in each other.

combustion

A reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat

carbon dioxide and water

products of combustion of hydrocarbons

mikhail tsvet

• invented chromatography in 1901 during his research on plant pigments.

• He used the technique to separate various plant pigments such as chlorophylls, xanthophylls and carotenoids.

chromatography

• a method of separation.

• it was used to separate colored materials (separations of colored materials are easy to observe) – hence, the name.

• But, today, chromatography is used to separate materials whether they are colored or not.

• The separation process is based on the fact that porous solids adsorb different substances to different extremes depending upon their polarity.

adsorption

• refers to the adhesion or stickiness of a substance to the surface of another substance, as opposed to

• where a liquid is soaked up into something like a sponge, cloth or filter paper. The liquid is completely absorbed into the absorbent material.

absorption

• which refers to a substance penetrating into the inner structure of another substance.

• refers to individual molecules, atoms or ions gathering on surfaces.

thin layer chromatography

• an easy, convenient and inexpensive way to determine how many components

• It can be used to identify the components as well.

distillation

• a process in which volatile liquids are separated & purified by using their boiling points.

• means taking the fermented ethanol and water mixture and adding heat to separate them

simple distillation and fractional distillation

types of distillation

simple distillation

used when substances in the mixture have significantly different boiling points.

fractional distillation

• used when substances in the mixture have close boiling points

• a process by which components in a chemical mixture are separated into different parts (called fractions) according to their different boiling points.

• used to purify chemicals and to separate mixtures to obtain their components

anti-bumping granules

• small pieces of silica; broken unglazed pottery works as well.

• This provides a nucleus on which gas bubbles grow, therefore avoiding the sudden production of large gas bubbles which can lead to ‘bumping’.

synge and martin in 1943

who discovered paper chromatography

capillary melting point

defined as the temperature range over which a small amount of solid in a thin-walled capillary tube first visibly softens (first drop of liquid) and then completely liquefies.