أكاديميا - كولنز - معاجم الجيب العلمية - الكيمياء - انكليزي - فرنسي - عربي الحرف ٢_ f

Academia - Collins - Pocket Scientific Dictionaries - Chemistry - English - French - Arabic Letter 2_ F


flame test
essai m de coloration

Flame test. This test can be used to determine the metal ions present in compounds.
A clean nichrome or platinum wire is immersed in hydrochloric acid and then in a sample of the compound to be tested. The wire to which some of the compound has stuck is placed in the hottest part of the flame. Compounds are characterized by specific colors (when heated):

Copper: green/blue
Calcium: Agri red
Sodium: yellow/orange
Potassium: Lilac
Barium: apple green
Lithium: bright red


flask
flacon m. flasque f

Hajla. Beaker Usually a glass vessel in which chemical reactions take place. Some of them have graduations that show the specific volumes.


fluorine (F2)
fluor m

Fluorine is a gaseous, non-metallic element in group VII of the periodic table. It is a halogen element and the most reactive element.

Fluorine is an active oxidizing agent that oxidizes even a radical
Chloride and water:

2CI- + F2 → 2F + Cl2
(aqueous) (aqueous) (gas) (aqueous)

2H2O + F2 → 4HF + O2
(gas) (gas) (gas) (liquid)

Carbon and fluorine compounds (fluorocarbons) are important refrigerants and aerosols.

Fluorine is extracted by electrolysis of molten fluoride, such as KHF2, and fluoride compounds are added to toothpaste to reduce tooth decay.
See polytetrafluoroethene.

formaldehyde (or methanal)
formaldehyde m. formal m


Antaldehyde (or methanal). A toxic gas that belongs to the family of organic compounds called aldehydes. It is used extensively in making ionomers and types of plastics such as Bakelite, melamine, and Formica.


formalin
formaline f

Formalin. An aqueous solution of formaldehyde is used to preserve typical biological samples.


formula
formula f

Formula.
See empirical formula and molecular formula.


fractional distillation (or fractionation)
distillation f fractionnée

Fractional distillation (or fractionation). A solvent can be separated from a solution
By simple distillation. As for the mixture of liquids with different boiling points, it is usually distilled and the resulting materials are collected (distillates), which boil in a specific range of temperatures. These distillates are called fractions. Diagram (p.) (172) shows how petroleum can be fractionally distilled.

The exact temperature range for these parts can vary depending on the output required most.


fructose
fructose m

Fructose, fructose. A sugar molecule with formula C6H1206 found in honey and golden syrup » Golden Syrup.

fuel
carburant m

fuel. A substance that releases heat energy when processed in some way. Energy is released in most types of fuel by combustion:

-Types of fossil fuels

natural gas
oil
Briquette
Peat
Coke
It burns in oxygen, releasing carbon dioxide and water.

- Organic fuels
wood
Waste materials

Nuclear fuel, such as uranium and plutonium, produces heat due to changes occurring inside the atom. Nuclear reactions generate huge amounts of energy.


functional group
group m function

Functional group. Reference to organic chemistry. It is the atom or group of atoms present in a molecule that is responsible for the distinctive properties of that molecule.

For example: CO2H - carboxylic acid
CHO - aldehyde
NH2 - amine

Functional groups in organic chemistry correspond to radicals in inorganic chemistry.
See radical.


fusion
fusion f

Fusion. Fusion This word means joining
Together”, and it has two special uses in chemistry:
1) Fusion is synonymous with melting. See latent heat.
2) Some nuclear reactions are based on the fusion of two atoms to form one atom. This is the opposite of fission and can release huge amounts of energy. The hydrogen bomb is a fusion weapon. Attempts are being made to use fusion reactions to generate electricity.