Please enable JavaScript.
Coggle requires JavaScript to display documents.
Research on Mole Concept - Coggle Diagram
Research on Mole Concept
The history behind the Avogadro’s hypothesis/law or principle
Gay-Lussac's Law of Gaseous Volume
: "Gases always combine with one another in a simple ratio by volume."
Dalton’s Atomic Theory
: "Elements combine with one another in a simple whole no. atomic ratio to form compounds."
Berzelius tried to co-relate
Gay-Lussac‘s law of Gaseous Volume
and
Dalton’s Atomic Theory
.
Berzelius: "Equal volumes of all gases under similar conditions of temperature and pressure contain equal number of atoms."
...implies that one compound atom of hydrogen chloride gas is made up of ½ atom of hydrogen and ½ atom of chlorine.
This conflicted with Dalton’s Atomic Theory
.
Avogadro
solved Berzelius's problem. He said, "An atom is the smallest particle of an element which can take part in a chemical reaction. It may or may not be capable of independent existence. A molecule is the smallest particle of an element or a compound, which is capable of independent existence."
Avogadro’s Hypothesis
: “Equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules."
...implies that one molecule of hydrogen chloride gas is made up of ½ molecule of hydrogen and ½ molecule of chlorine. Since a molecule is made up of two or more atoms so ½ molecule is possible and may contain one or two atoms.
Application of Avogadro's Law
Establishes a relationship between relative vapour density and its relative molecular mass:
The vapour density of a gas is double its relative molecular mass.
Explains Gay-Lussac's Law of combining volumes:
The Gay-Lussac law explained that the ratio between gaseous product and reactants can be expressed in whole numbers. Avogadro explained that under the same pressure and temperature, equal volumes of gases will contain the same amount of molecules.
Determines the atomicity and molecular formula of gases:
The law helps determine the number of atoms of the elements present in one molecule of the substance. For example, the atomicity of Oxygen (O2) is 2.
Modified Dalton's Atomic Theory
Atom is not considered an indivisible
Atoms of the same element may have different atomic masses
Atoms of different elements may have the same atomic masses
The ratio in which different atoms combine with one another may be fixed and integral but may not always be simple
Atom is the smallest particle that takes place in chemical reaction
Atom is no longer indestructible