Niels Bjerrum


Niels Janniksen Bjerrum was a Danish chemist.
Niels Bjerrum was the son of ophthalmologist Jannik Petersen Bjerrum, and started to study at University of Copenhagen in 1897. He received his Master's degree in 1902 and his Doctor's degree in 1908, and did research in coordination complex chemistry under Sophus Mads Jørgensen. He became a docent in 1912, and in 1914 he became professor of chemistry at the Royal Agricultural College in Copenhagen, as successor of Odin Tidemand Christensen. He stayed on this post until his retirement in 1949, and from 1939 to 1946 he was also the Director of the College.
He is noted for the theory behind the Bjerrum length, and the Bjerrum plot. Bjerrum also performed some of the first research on the measurement of soil acidity.
His son Jannik Bjerrum also became a chemist and was active in the area of complex chemistry.

Contribution to electrolytes theory

Between 1916 and 1926 he investigated the properties of electrolytic solutions in regards to their dissociation and association in German journals like Z. anorg. allgem. Chem. and Ergebnisse der exakten Naturwissenschaften. He also published in the British journal Transactions of the Faraday Society .
He introduced the quantity osmotic coefficient in relation to non-ideal solutions of electrolytes.