Calculate the mass of 2.56*10^24 formula units of aluminum dichromate.
I must tell you I get confused every time someone starts talking formula units and formula weights (mass). I think formula unit x formula mass = mass in grams.
To calculate the mass of 2.56 * 10^24 formula units of aluminum dichromate, we need to know the molar mass of the compound.
1. Determine the formula of aluminum dichromate:
Aluminum is represented by the symbol Al, and dichromate is represented by the formula (Cr2O7)2-. Therefore, the formula for aluminum dichromate is Al(Cr2O7)3.
2. Calculate the molar mass of aluminum dichromate:
- The molar mass of aluminum (Al) is 26.98 g/mol.
- The molar mass of chromium (Cr) is 51.996 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
The molar mass of aluminum dichromate can be calculated as follows:
Molar mass of Al(Cr2O7)3 = (1 * molar mass of Al) + (3 * molar mass of Cr) + (21 * molar mass of O)
Substituting the values:
Molar mass of Al(Cr2O7)3 = (1 * 26.98 g/mol) + (3 * 51.996 g/mol) + (21 * 16.00 g/mol)
3. Calculate the mass of 2.56 * 10^24 formula units of aluminum dichromate:
Now that we have the molar mass, we can convert formula units to grams:
Mass (g) = Number of formula units * molar mass
Mass (g) = (2.56 * 10^24) * (molar mass of Al(Cr2O7)3)
Substituting the value of the molar mass, the calculations would yield the mass of 2.56 * 10^24 formula units of aluminum dichromate.