The molecular weight of Histidine [C₆H₉N₃O₂] is 155.15522.

Histidine (C₆H₉N₃O₂) is an organic compound of four elements: Carbon, Hydrogen, Nitrogen, and Oxygen. The molecular weight of Histidine is 155.15522 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of all its elements.

CALCULATION PROCEDURE: Histidine  [C₆H₉N₃O₂] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Histidine molecule.
From the chemical formula, you will know different atoms and their number in a Histidine molecule. The chemical formula of Histidine is C₆H₉N₃O₂. From the chemical formula, you can find that one molecule of Histidine consists of six Carbon (C) atoms, nine Hydrogen (H) atoms, three Nitrogen (N) atoms, and two Oxygen atoms.

Step 2: Find out the atomic weights of each atom (from the periodic table).

Atomic weight of Carbon (C): 12.0107 (Ref: Jlab-ele006)
Atomic weight of Hydrogen (H): 1.008 (Ref: Lanl-1)
Atomic weight of Nitrogen (N): 14.00674 (Ref: Jlab-ele007)
Atomic weight of Oxygen (O): 15.9994 (Ref: Jlab-ele008)

Step 3: Calculate the total weight of each atom in a Histidine molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Histidine: 6
Atomic weight of Carbon (C): 12.0107
Total weight of Carbon atoms in Histidine: 12.0107 x 6 = 72.0642

Number of Hydrogen atoms in Histidine: 9
Atomic weight of Hydrogen (H): 1.008
Total weight of Hydrogen atoms in Histidine: 1.008 x 9 = 9.072

Number of Nitrogen atoms in Histidine: 3
Atomic weight of Nitrogen (N): 14.00674
Total weight of Nitrogen atoms in Histidine: 14.00674 x 3 = 42.02022

Number of Oxygen atoms in Histidine: 2
Atomic weight of Oxygen (O): 15.9994
Total weight of Oxygen atoms in Histidine: 15.9994 x 2 = 31.9988

Step 4: Calculate the molecular weight of Histidine by adding up the total weight of all atoms.

Molecular weight of Histidine: 72.0642 (Carbon) + 9.072 (Hydrogen) + 42.02022 (Nitrogen) + 31.9988 (Oxygen) = 155.15522

So the molecular weight of Histidine is 155.15522.

Histidine [C₆H₉N₃O₂] Molecular Weight Calculation

REFERENCES:

• Lanl-1: https://periodic.lanl.gov/1.shtml 
• Jlab-ele006: https://education.jlab.org/itselemental/ele006.html 
• Jlab-ele007: https://education.jlab.org/itselemental/ele007.html
• Jlab-ele008: https://education.jlab.org/itselemental/ele008.html
  

See also:

• Hydrogen chloride molecular weight calculation