أكاديميا - كولنز - معاجم الجيب العلمية - الكيمياء - انكليزي - فرنسي - عربي الحرف ١_ f

Academia - Collins - Pocket Scientific Dictionaries - Chemistry - English - French - Arabic Letter 1_ F


faraday (F)
faraday m

Faraday. The amount of electrical charge possessed by a mole of electrons (about 96,500 coulombs). This amount of electricity is necessary to liberate one mole of atoms of a monovalent element such as silver during electrolysis:

Ag+ + e- > Ag

One mole of silver atoms Ag

One mole of electrons e-

One mole of silver ions Ag+


Fehling's test
essai m de Fehling

Fehling's test. A test used to detect certain organic factors. Using this test, organic reducing agents can distinguish aldehydes from ketones and sugars such as glucose from starch. Fehling's solution is a mixture of copper (II) sulfate, sodium hydroxide, and sodium and potassium tartrate. When the solution is heated with a suitable reference agent, such as glucose or ethanol, the copper (II) salt reverts to a red precipitate of copper oxide (Cu₂O) (I).


fermentation
fermentation f

Fermenting. A process in which chemical changes occur in organic chemicals using living organisms such as yeasts and bacteria. Changes occur by enzymes that act as catalysts.

An important example of this is the change of sugars into ethanol by yeast:

C6 H12O6 > 2C2H5OH + 2CO2

Carbon dioxide - ethanol - glucose

This reaction is used in making alcoholic beverages:

- Malted barley
beer (beer)
Whiskey (after fractional distillation)

- Fruit, such as grapes
wine
Sherry and Port
Brandy (after fractional distillation).

fertilizer
engrais m

Fertilizer A substance added to the soil to replace nutrients removed by plants. Fertilizers may be natural, such as manure and mixed manure, or artificial, such as ammonium nitrate and super phosphate. Compounds containing nitrogen, phosphorus, and potassium (NPK) constitute the main components of synthetic fertilizers. Adding fertilizers to the ground is an important part of the nitrogen cycle.


filter
filter m

candidate . An insoluble solid can be separated from a liquid by pouring the mixture onto a filter paper into a filter funnel, and the liquid (or solution) passes through the paper. It is called a leak. The solid material (called residue) remains in the filter paper. The whole process is called filtration.


fission
fission f

Dichotomy. This term means "disintegration." If a molecule splits into two or more parts, it is said to be fission.
The fission of a large atom in nuclear reactions, such as the fission of a uranium atom into two smaller ones such as barium and krypton, leads to the release of huge amounts of energy.


fixing nitrogen
Fixation of the azote

Installation of nitrogen. Any process that converts atmospheric nitrogen into compounds useful as fertilizers. Fixation is carried out through the Haber process and is carried out by bacteria found on the roots of some plants such as peas and beans.


flame
flame f

flame. When materials interact and produce hot gases, these gases often give off light and heat energy. This is known as flame. Flame types differ in their colors and temperatures. The flame of a gas burner is yellow in color if the air hole is closed because the resulting flame contains tiny glowing particles of unburned carbon. When the air hole is open (as shown in the drawing), the flame is composed of different parts with different temperatures. The hottest point is where the X sign is located.

Burning flame
External cone.
Inner cone
Unburned gas
Burner tube