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Antoine Laurent Lavoisier
Antoine Laurent Lavoisier was a French chemist, born in Paris, and considered the founder of modern chemistry. (1743-1794).
He stated that mass is not created or destroyed during chemical reactions.
He also discovered that water was a compound made of hydrogen and oxygen.
Lavoisier showed that oxygen was needed for combustion. (Fire was not caused by phlogiston, as most people believed during his time.)
Lavoisier's work led John Dalton to publish his atomic theory in 1808.
Lavoisier debunked Phlogiston Theory
Balancing equations is a necessary skill in chemistry and it reflects the fact that matter is neither created nor destroyed, according to the law of conservation of mass. Antoine Laurent Lavoisier, a French chemist, published this law in the year 1789.
The law states that the number of atoms before and after the reaction does not change. Atoms are not lost or gained. Instead, atoms are recycled in chemical reactions and new molecules are produced.
Here is the equation for the combustion of Ethyl Alcohol:
Here is the equation for the combustion of Ethyl Alcohol:
CH3CH2OH + 3O2 => 2CO2 + 3H2O
CH3CH2OH + 3O2 => 2CO2 + 3H2O
After the reaction, the fuel and oxygen are no longer available; they have been converted to carbon dioxide and water.
Also, note that the number of atoms has not changed. There are 2 carbon atoms before and after reaction. Likewise, there are 6 hydrogen atoms before and after the reaction. Lastly, the number of oxygen atoms (7) also remains unchanged. The atoms have been recycled to make new compounds.
The Combustion of Isopropyl Alcohol!
The Combustion of Isopropyl Alcohol!
Word Equation: Isopropyl Alcholol + Oxygen Gas --> Water + Carbon Dioxide Gas
Chemical Equation: CH3CH0HCH3 + O2 --> H20 + CO2
Balanced Chemical Equation: 2CH3CH0HCH3 + 9O2 --> 8H20 + 6CO2
The Electrolysis of Water!
The Electrolysis of Water!
Electrolysis
Electrolysis
Word Equation: Water --> Hydrogen Gas + Oxygen Gas
Chemical Equation: H20 --> H2 + O2
The formula for each molecule above is correct. However, as you can see, it seems that we have gained an extra oxygen atom. This is not possible. Something is wrong.
To account for this, we need to balance the equation. Read to the right.
Balanced Chemical Equation: 2H20 --> 2H2 + O2
Balancing this equation will satisfy the law of conservation of mass.
Write a 2 before the water molecule. 2 water molecules can result in 1 oxygen gas molecule after the reaction. As you can see, the number of oxygen atoms is the same before and after the reaction.
Lastly, if we write a 2 before the hydrogen gas molecule, we will have balanced the number of hydrogen atoms before and after the reaction. The total number of atoms is the same before and after the reaction.
The Combustion of Hydrogen Gas!
The Combustion of Hydrogen Gas!
Word Equation: Hydrogen Gas + Oxygen Gas --> Water
Chemical Equation: H2 + O2 --> H20
Balanced Chemical Equation: 2H2 + O2 --> 2H20
The Decomposition of Hydrogen Peroxide!
The Decomposition of Hydrogen Peroxide!
Word Equation: Hydrogen Peroxide --> Water + Oxygen Gas
Chemical Equation: H202 --> H20 + O2
Balanced Chemical Equation: 2H202 --> 2H20 + O2
More Practice balancing equations: Balancing Chemical Equations Rags to Riches Game
Another Conservation of Mass Link: Conservation of Mass
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