90 likes | 191 Views
The Proclaimer ( O.Fr. la voisier). The Father of Chemistry. Antoine Lavoisier (1743-1794) was a taxman He was also a methodical scientist, who made careful, orderly measurements on weights, volumes and products of reaction using apparatus like the Gazometre
E N D
The Father of Chemistry • Antoine Lavoisier (1743-1794) was a taxman • He was also a methodical scientist, who made careful, orderly measurements on weights, volumes and products of reaction using apparatus like the Gazometre • His fundamental belief was that the weight of matter would be conserved through any reaction • This concept led to our modern understanding of combustion and respiration involving the part of “common air” he called OXYGEN
The discovery of Oxygen: the demise of phlogiston • In 1789 Lavoisier heated mercuric oxide in a closed system and measured the amount of oxygen gas liberated. • He reversed the experiment by heating the mercury formed: it took up exactly the amount of oxygen previously made!
A Tale of Two Scientists • Joseph Priestley was a social and religious revolutionary. In contrast he was rather a conservative chemist who believed in the incorrect phlogiston theory until the day he died • Antoine Lavoisier was a respected member of the pre-revolutionary establishment in Paris. In contrast his radical scientific ideas gave birth to modern Chemistry • In 1794 Priestley fled by ship to America while Lavoisier, aged 51, was executed in Paris
N names • “Common Air” had now been established to consist partly of Oxygen and partly of Fixed Air • The majority of it did not support life or combustion and was called: • Foul Air (by Scheele) and, later, Noxious or Mephic Air (by Black’s student Daniel Rutherford in 1772) • Azote (by Lavoisier in 1789) • Nitrogène (by the industrial chemist and French government Minister, Jean Antoine Chaptal in 1790: He kept his head!) • Stickstoff (i.e. literally “suffocating material” in Germanic nations)
The First Aeronomer • Joseph Gay Lussac (1778-1850) ascended in a balloon to 6-7km in 1802 • He determined that the concentration of gaseous oxygen in the atmosphere remained constant (~20%) as a function of altitude • In 1809 he showed that gases combine in very simple proportions by volume. This work inspired Avogadro in 1811…as we shall see next time
World Revolution and Order • Revolution in America (1775-1783) • Storming of the Bastille (1789) • United Irish Patriots rebellion (1798) • Napoleon Bonaparte was captured in 1815 and order restored over Europe. • The Industrial Revolution takes over based on careful measurement and sound principles
Art of the Time • Goya’s: “Execution of the Defenders of Madrid, 3rd May, 1808” (1814)
Discovery: 1770-1815 • Gases take over from “airs” • Oxygen, Hydrogen and many other gases discovered • Conservation of Mass Law stated • Oxidation and Reduction proposed • One volume of Oxygen found to combine with exactly two volumes of Hydrogen to form Water • The Science of Chemistry is born