Arrhenius
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| Acids/Bases - Theory |
History
Explore the discoverer's biography, including general facts about his life and anecdotes regarding how he made this particular discovery. Also see other significant scientific discoveries built largely on this concept and other real-world applications in history that may not still be relevant.
Discoverer/Developer
Svante Arrhenius (1859-1927) was born in Vik, Sweden. He taught himself to read at age three and learned arithmetic at a young age from his father's accounting. Electrolytic conductivity was the subject of his dissertation, which was, in effect, given a grade of D by the professors reviewing it. However, this work was the basis of his Nobel Prize in Chemistry. Arrhenius became a professor at Stockholm University College. In 1884, he postulated the definition of acids and bases that has come to take his name. Five years later he proposed the idea of activation energy, that for a reaction to take place the molecules have to be given a certain amount of energy. Other topics on which Arrhenius did research included astronomy and the carbon dioxide level in Earth's atmosphere. Arrhenius was the first to theorize that carbon dioxide levels in the atmosphere could change the temperature by the greenhouse effect. However, he saw this completely as a beneficial phenomenon, because a warmer world would have higher plant yields according to him. Arrhenius was on the Nobel Physics Committee, where he advocated for people he liked to receive a Nobel Prize and his enemies to be denied one. Arrhenius himself won the Nobel Prize in Chemistry in 1903.
Concept Definition
Study the primary definition of this concept, broken into general, basic, and advanced English definitions. Also see the mathematical definition and any requisite background information, such as conditions or previous definitions.
Basic
An Arrhenius acid dissociates to form H3O+ (hydronium ions) when dissolved in water, while an Arrhenius base dissociates to form OH- (hydroxide ions) when dissolved in water.
Advanced
An Arrhenius acid dissociates to form H3O+ (hydronium ions) when dissolved in water, while an Arrhenius base dissociates to form OH- (hydroxide ions) when dissolved in water. Many substances that are considered acids and bases are excluded when this definition is used to determine acids and bases.
Vocabulary
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Classroom Demonstations
Investigate lab procedures suitable for live classroom demonstrations or guided student exploration.
Students requiring adaptations to gain the full benefit of a demonstration may find a worksheet with guided observations useful. Alternatively, a teacher may wish to use a worksheet with guided observations to model what observations all students should be making during a demonstration.
The Demonstration Observation Worksheet is available in
Colorful Electrolysis -- Decomposition of Water
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Colorful Electrolysis -- Decomposition of Water
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The formation of H+ causes the color of bromothymol blue change to yellow. There is more gas produced on the cathode side than on the anode side, indicating that there are more moles of hydrogen atoms than oxygen atoms in water molecules (the mole ratio of hydrogen to oxygen in water molecules is not 1:1, but indeed 2:1). The formation of H+ is temporary, and after the electric circuit setup is removed and the solution is allowed to sit for 5 minutes, the color of the solution changes back to its original color [blue]. ______________________________________________________________________________________________________ Related videos can be view here: Animation
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