A protein found in some types of wood-rotting fungi is 0.40% copper by mass. Each protein molecule is known to contain 4 copper atoms. What is the approximate molecular weight of this compound?
[4*Cu/(mass sample)]*100 = 0.4
Solve for mass sample=molar mass.
To find the approximate molecular weight of the compound, we need to know the molecular weight of copper and the percentage of copper in the protein.
Step 1: Find the molecular weight of copper.
The atomic weight of copper (Cu) is approximately 63.55 g/mol.
Step 2: Calculate the mass of copper in one molecule of the protein.
Since each protein molecule contains 4 copper atoms, the mass of copper in one protein molecule can be calculated as follows:
Mass of copper = 4 atoms x (atomic weight of copper) = 4 x 63.55 g/mol
Step 3: Calculate the mass of the protein molecule.
We know that the protein is 0.40% copper by mass. So, the mass of the protein is:
Mass of protein = (Mass of copper) / (Percentage of copper) x 100.
Mass of protein = (4 x 63.55 g/mol) / (0.40/100) = (4 x 63.55 g/mol) / (0.004) = 4 x 63.55 g/mol x (1/0.004) = 4 x 63.55 g/mol x 250 = 635.5 g/mol x 250 = 158,875 g/mol.
Therefore, the approximate molecular weight of this protein is approximately 158,875 g/mol.