What is the molar mass of hemocyanin?
Nominally, 75000 daltons
It is a respiratory protein, similar to hemoglobin, but centered around copper instead of iron. As a protein, it it usually measured in Daltons, not molecular weight.
Molecular masses of proteins are often expressed in daltons. For example, a molecule of a protein with molar mass 64000 g⋅mol−1 has a mass of 64 kDa. - Berg, Jeremy M.; Tymoczko, John L.; Stryer, Lubert (2007). "2". Biochemistry (6th ed.). New York: Freeman. p. 35. ISBN 978-0-7167-8724-2.