Historical figure · Pearson Edexcel International GCSE revision on Incandio

Friedrich Wöhler

Who Made Urea Without A Kidney · Chemist · 1800–1882

The chemist who made urea from materials that had never been alive, and who found with Liebig that two substances can hold exactly the same atoms and be nothing alike.

Defend these ideas against Wöhler

Incandio is a free revision platform for the Pearson Edexcel International GCSE, and on it a topic counts as mastered only once you have learned it, proved it in questions, taught it back and defended it against the person with the strongest claim on it. Friedrich Wöhler is that person for 2 topics on the course:

• Excretion: Getting Rid of What You Made — Biology
• What Organic Chemistry Is — Chemistry

Who was Wöhler?

Friedrich Wöhler was born near Frankfurt in 1800, qualified in medicine, and then went to Stockholm to study under Berzelius, the most authoritative chemist in Europe. In 1828, trying to prepare ammonium cyanate, he obtained crystals that turned out to be urea — the compound excreted by the kidney. He wrote to Berzelius that he could make urea without needing a kidney, whether of man or of dog. Chemistry at the time divided sharply between the mineral world and the organic one, and held that compounds of living things required a vital force present only in living things. Wöhler had made one without it. He did not claim to have overturned the doctrine, and was careful to say so; vitalism faded over the following decades rather than collapsing in 1828, and Berzelius was never persuaded. His second contribution has proved at least as deep. With his lifelong friend Justus von Liebig he showed that silver cyanate and silver fulminate contain the same atoms in the same proportions and are entirely different substances — the phenomenon Berzelius named isomerism, and the reason a molecular formula alone can never identify a compound. He also isolated aluminium and beryllium, prepared calcium carbide and obtained acetylene from it, and built at Göttingen a teaching laboratory that trained a large share of the working chemists of the century.

Major achievements

• Synthesised urea in 1828 from materials that had never been alive
• Showed with Liebig that silver cyanate and silver fulminate are isomers
• Isolated aluminium in 1827, and beryllium the following year
• Prepared calcium carbide and obtained acetylene from it
• Built the Göttingen laboratory that trained a generation of chemists

Life in brief

• 1800 — Born near Frankfurt: Son of a veterinary surgeon; qualifies later in medicine.
• 1823 — Stockholm: Studies under Berzelius, and learns the analytical methods of the day.
• 1827 — Aluminium: Isolates the metal, and beryllium the following year.
• 1828 — Urea: Obtains urea while attempting ammonium cyanate, and writes to Berzelius.
• 1832 — Work with Liebig: The benzoyl radical papers begin a fifty-year collaboration.
• 1836 — Göttingen: Takes the chair, and builds the teaching laboratory he is remembered for.
• 1882 — Dies at Göttingen: After training a large part of the century's working chemists.

Explore the life of Wöhler — five chapters

1. A Year With Berzelius — A physician who never practised, learning to weigh
2. Trying to Make Something Else — 22 February 1828
3. Vitalism Did Not Collapse in 1828 — What actually happened over the following forty years
4. The Same Atoms, and a Different Substance — Isomerism, and why a formula is not enough
5. The Laboratory at Göttingen — Aluminium, acetylene, and a generation of chemists

Read the five-chapter life of Friedrich Wöhler →

Where Wöhler appears in your course

Friedrich Wöhler has a genuine claim on 4 lessons of the Pearson Edexcel International GCSE science course built into Incandio:

• Excretion: Getting Rid of What You Made — Biology: In 1828 Wöhler heated a mineral salt and obtained urea — the substance this lesson is about — with no living thing involved at all. He wrote to Berzelius that he could make urea without needing a kidney, whether of man or of dog, and in doing so struck the first serious blow against the belief that the chemistry of living things was different in kind from any other. What his flask could never show him was the road a body takes to the same substance: the surplus amino acids, the liver, the ammonia too toxic to keep.
• What Organic Chemistry Is — Chemistry: Isomerism, the last term this page defines, was not deduced from theory — it was forced on chemistry by a measurement nobody wanted. Wöhler and Liebig analysed silver cyanate and silver fulminate, found precisely the same atoms in precisely the same proportions, and could not deny that the two substances were nothing alike. Wöhler is also the man who made urea from materials that had never been alive, which is why the word organic no longer means what it once did. He is the right person to ask what it feels like when an analysis refuses to agree with the doctrine.
• Alcohols — Chemistry: The whole idea of a functional group — that one part of a molecule can be picked out as the part that reacts, while the rest merely comes along — had to be established, and it was established by Wöhler and Liebig. In 1832 they showed that a particular group of atoms, which they called the benzoyl radical, passed unchanged through a whole series of different reactions, appearing intact in every product. Berzelius called it the beginning of a new day in chemistry. That is the direct ancestor of saying that –OH is what makes an alcohol an alcohol, whatever chain it is attached to.
• Working Out Esters, And What They Are For — Chemistry: This page arrives at a striking fact: ethyl ethanoate, methyl propanoate and propyl methanoate all have the molecular formula C₄H₈O₂ and all smell different. That is isomerism, and Wöhler found it — but he found it in silver cyanate and silver fulminate, where the difference showed up as one compound detonating and the other not. Here the same principle shows up as a difference you can detect with your nose. He is the right person to ask why rearranging the same atoms should change a property as intimate as a smell.

Begin

• Start a conversation with Wöhler — a dramatised, historically grounded AI portrayal
• Read the Historical Brief
• Explore the life of Wöhler — five chapters
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