In 1893, which Swiss chemist was the first to understand the molecular structures of inorganic substances – chemical compounds that do not contain carbon?
Alfred Werner
Understanding Inorganic Structures: The Pioneering Work of Alfred Werner
The question asks about the Swiss chemist who, in 1893, was the first to significantly advance our understanding of the molecular structures of inorganic substances. Inorganic substances are chemical compounds that typically do not contain carbon-hydrogen bonds, distinguishing them from organic compounds.
In 1893, Alfred Werner proposed his Coordination Theory, which revolutionized the understanding of how atoms are bonded together in many inorganic compounds, particularly coordination complexes. Before Werner, the structures of many inorganic substances were poorly understood. His theory provided a framework for explaining the properties, isomerism, and structures of these complex inorganic materials.
Alfred Werner's Contribution to Inorganic Structures
- Alfred Werner (1866–1919) was a Swiss chemist.
- His most significant contribution was the development of the Coordination Theory in 1893.
- This theory explained the bonding in coordination compounds, where a central metal atom or ion is surrounded by a group of ligands (ions or molecules).
- He introduced the concept of "coordination number" and described the spatial arrangements (stereochemistry) of ligands around the central metal, such as octahedral, square planar, and tetrahedral geometries.
- His work provided the first clear picture of the molecular structures of many complex inorganic substances.
- For this groundbreaking work, he was awarded the Nobel Prize in Chemistry in 1913, making him the first inorganic chemist to receive this honor.
Analyzing the Options
Let's briefly look at the other chemists mentioned in the options and their main contributions to understand why Alfred Werner is the correct answer in the context of understanding inorganic molecular structures in 1893.
| Chemist | Key Contribution Area | Associated Time Period (Major Work) |
|---|---|---|
| Alfred Werner | Coordination Chemistry, Structure of Inorganic Complexes | Late 19th / Early 20th Century (Coordination Theory: 1893) |
| William Ramsay | Discovery of Noble Gases (Argon, Neon, Krypton, Xenon) | Late 19th Century (Discovery of Argon: 1894) |
| George de Hevesy | Radiochemistry, Use of Radioactive Tracers, Discovery of Hafnium | Early to Mid-20th Century |
| John Dalton | Atomic Theory | Early 19th Century (Atomic Theory Postulates: 1803) |
Based on their contributions and the timeline, Alfred Werner is the chemist credited with first understanding the molecular structures of inorganic substances through his Coordination Theory, which he proposed in 1893. The other chemists made significant contributions to chemistry, but not specifically to revolutionizing the understanding of inorganic molecular structures in the way Werner did at that time.
Conclusion
The Swiss chemist who was the first to understand the molecular structures of inorganic substances in 1893 was Alfred Werner, through his revolutionary Coordination Theory.
Revision Table: Key Chemists & Contributions
| Chemist | Nationality | Major Field | Key Achievement (Relevant Period) |
|---|---|---|---|
| Alfred Werner | Swiss | Inorganic Chemistry (Coordination Chemistry) | Coordination Theory (1893) |
| William Ramsay | British | Physical Chemistry | Discovery of Noble Gases (e.g., Argon in 1894) |
| George de Hevesy | Hungarian/Swedish | Radiochemistry | Pioneer in radioactive tracers (early 20th century) |
| John Dalton | British | Chemistry/Physics | Modern Atomic Theory (early 19th century) |
Additional Information: Coordination Theory and Inorganic Structures
Alfred Werner's Coordination Theory was a major step forward because it provided a consistent explanation for the bonding and structure of coordination compounds, which make up a vast class of inorganic substances. His theory introduced several key concepts:
- Primary Valency: This corresponds to the oxidation state of the central metal ion.
- Secondary Valency: This corresponds to the coordination number, which is the number of ligands directly bonded to the central metal ion.
- Ligands: Ions or molecules that coordinate to the central metal atom/ion.
- Stereochemistry: The spatial arrangement of ligands around the central metal ion (e.g., octahedral, square planar).
Werner's experimental work, particularly on isomers of coordination complexes, provided strong evidence for his theory and the predicted geometries. This theory remains fundamental to the study of inorganic chemistry and understanding the structures of many important inorganic materials, from catalysts to biological molecules containing metal ions.
Important Questions from Atomic Structure
The four quantum numbers of the valence electron of potassium atom are:
What is the increasing order for the values of e/m for
Which of the following pairs of 'number – composition' is correct?
I. Atomic number – number of protons
II. Mass number – Sum of number of neutrons and protons
The radius of an atomic nucleus is of the order of
An element with atomic number 103 has a nuclear charge of +103. So its charge would be balanced by ________.
