LAWS OF CHEMICAL COMBINATION
Elements combine to form compounds. This combination of elements is governed by five basic laws.
1. Law of Conservation of mass
2. Law of Definite proportion
3. Law of Multiple proportion
4. Gay Lussac’s law of gaseous volumes
5. Avogadro’s law
LAW OF CONSERVATION OF MASS
This law was put forth by Antoine Lavoisier.
The law states that Matter can neither be created nor destroyed.
During any physical or chemical change, the total mass of reactants is equal to the total mass of products.
LAW OF DEFINITE PROPORTION
This law was put forth by a French chemist, Joseph Proust
The law states that a given compound always contains exactly the same proportion of elements by weight.
The law means that irrespective of the source, a given compound always contains same elements combined
together in the same proportion by mass.
EXAMPLE: The mass percentage of hydrogen and oxygen in water is 11.11 % hydrogen and 88.89 % oxygen.
LAW OF MULTIPLE PROPORTION
This law was proposed by Dalton
The law states that if two elements can combine to form more than one compound, the masses of one element
that combine with a fixed mass of the other element, are in the ratio of small whole numbers.
Example: Hydrogen combines with oxygen to form water and hydrogen peroxide.
Example: Carbon combines with oxygen to form carbon monoxide and carbon dioxide.
GAY LUSSAC’S LAW OF GASEOUS VOLUMES
This law was put forward by Gay Lussac.
The law states that when gases combine or are produced in a chemical reaction they do so in a simple ratio by
volume, provided all gases are at the same temperature and pressure.
When two gases combine in a chemical reaction, they do so in a simple ratio by volume.
Thus, the volumes of hydrogen and oxygen which combine (i.e., 100 mL and 50 mL) bear a simple ratio of 2:1.
When two gases are produced in a chemical reaction, they do so in a simple ratio by volume.
AVOGADRO’S LAW
This law was put forward by Avogadro.
The law states that equal volumes of all gases at the same temperature and pressure should contain equal
number of molecules.
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Elements combine to form compounds. This combination of elements is governed by five basic laws.
1. Law of Conservation of mass
2. Law of Definite proportion
3. Law of Multiple proportion
4. Gay Lussac’s law of gaseous volumes
5. Avogadro’s law
LAW OF CONSERVATION OF MASS
This law was put forth by Antoine Lavoisier.
The law states that Matter can neither be created nor destroyed.
During any physical or chemical change, the total mass of reactants is equal to the total mass of products.
LAW OF DEFINITE PROPORTION
This law was put forth by a French chemist, Joseph Proust
The law states that a given compound always contains exactly the same proportion of elements by weight.
The law means that irrespective of the source, a given compound always contains same elements combined
together in the same proportion by mass.
EXAMPLE: The mass percentage of hydrogen and oxygen in water is 11.11 % hydrogen and 88.89 % oxygen.
LAW OF MULTIPLE PROPORTION
This law was proposed by Dalton
The law states that if two elements can combine to form more than one compound, the masses of one element
that combine with a fixed mass of the other element, are in the ratio of small whole numbers.
Example: Hydrogen combines with oxygen to form water and hydrogen peroxide.
Example: Carbon combines with oxygen to form carbon monoxide and carbon dioxide.
GAY LUSSAC’S LAW OF GASEOUS VOLUMES
This law was put forward by Gay Lussac.
The law states that when gases combine or are produced in a chemical reaction they do so in a simple ratio by
volume, provided all gases are at the same temperature and pressure.
When two gases combine in a chemical reaction, they do so in a simple ratio by volume.
Thus, the volumes of hydrogen and oxygen which combine (i.e., 100 mL and 50 mL) bear a simple ratio of 2:1.
When two gases are produced in a chemical reaction, they do so in a simple ratio by volume.
AVOGADRO’S LAW
This law was put forward by Avogadro.
The law states that equal volumes of all gases at the same temperature and pressure should contain equal
number of molecules.
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