Friedrich Wohler's Synthesis of Urea: Mechanism & Experiment

Instructor: Laura Foist

Laura has a Masters of Science in Food Science and Human Nutrition and has taught college Science.

Friedrich Wohler performed an experiment attempting to form ammonium cyanate, instead he dispelled a commonly held theory and created urea. We will learn about this experiment in this lesson.

An Important Experiment

In chemistry, we often separate the study of organic and inorganic compounds. This is because the types of reactions and how they react tend to be really different between the two fields of chemistry. They are so different, in fact, that prior to the 1820s scientists believed that there was something fundamentally different between organic and inorganic compounds. They believed that the only way that something could become organic was through a 'vital force' which was found in living creatures. This entire belief was completely dispelled when Friedrich Wohler created urea from non-organic compounds.

Wohler was not attempting to dispel the vital force theory during this experiment, he was simply trying to make ammonium cyanate. When he ended up making urea it dispelled the vital force theory. This was an important experiment which led to the start of organic chemistry as we know it today.

Urea is a great fertilizer, and comes from the urine of animals. It contains a carbon, doubled bonded to an oxygen, and bound to two nitrogen atoms, the nitrogen atoms each have two hydrogen atoms.

The Mechanism

The first step in this reaction takes lead cyanate (silver or potassium cyanate can also be used) and reacts it with ammonia and water. Wohler expected the ammonia to form a salt with the cyanate, forming ammonia cyanate. The first step of this reaction occurred just as he expected it, with the salts rearranging to form ammonia cyanate:


Prior to the salt rearrangement, the ammonia and water needs to rearrange hydrogen atoms to form a negative and positive charged particles, this reaction actually occurs twice, with two water molecules and two ammonia molecules
Mechanism step 1



The positive charge on the lead combines with two hydroxide molecules, and the negative charge on the cyanate forms with the ammonium to form ammonium cyanate
Mechanism step 2


But, the reaction doesn't stop there, instead the ammonium decomposes, forming ammonia and cyanic acid:


The ammonium cyanate quickly decomposes, with ammonia and cyanic acid forming
Mechanism step 3


To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account
Support