The formula for rust can be represented by Fe2O3. How many moles of Fe are present in 21.3g of the compound? Please help. I am SO confused on all of this!!
What's the percent Fe in Fe2O3? That's (2*atomic mass Fe/molar mass Fe2O3)*100.
Then 21.3 g x fraction iron = g Fe.
To find the number of moles of Fe in 21.3g of Fe2O3, you need to use the molar mass of Fe2O3 and the given mass.
1. Determine the molar mass of Fe2O3:
- The molar mass of Fe = 55.85 g/mol.
- The molar mass of O = 16.00 g/mol.
- Fe2O3 consists of 2 Fe atoms and 3 O atoms.
- So, the molar mass of Fe2O3 = (2 * 55.85 g/mol) + (3 * 16.00 g/mol) = 159.70 g/mol.
2. Calculate the number of moles:
- Number of moles = given mass / molar mass.
- Number of moles of Fe2O3 = 21.3g / 159.70 g/mol ≈ 0.1334 mol.
3. Determine the moles of Fe:
- Since the ratio of Fe to Fe2O3 is 2:1, the number of moles of Fe will be half of the moles of Fe2O3.
- Number of moles of Fe = 0.1334 mol / 2 = 0.0667 mol.
Therefore, there are approximately 0.0667 moles of Fe present in 21.3g of Fe2O3.
To find the number of moles of Fe in 21.3g of Fe2O3, you need to use the molar mass of Fe2O3 and the molar mass of Fe.
First, let's find the molar mass of Fe2O3:
- The molar mass of Fe is 55.8 g/mol.
- The molar mass of O is 16.0 g/mol.
Since there are three oxygen atoms in Fe2O3, the total mass of oxygen in Fe2O3 is 3 * 16.0 = 48.0 g/mol.
Thus, the molar mass of Fe2O3 is 2 * 55.8 + 48.0 = 159.6 g/mol.
Next, we can use the molar mass of Fe2O3 to find the moles of Fe in 21.3g:
- Divide the mass of Fe2O3 by its molar mass:
Moles = Mass / Molar mass
Moles of Fe2O3 = 21.3g / 159.6 g/mol
Finally, we can calculate the moles of Fe by multiplying the moles of Fe2O3 by the ratio between the moles of Fe and moles of Fe2O3:
- Multiply the moles of Fe2O3 by the ratio 2 / 1 (since there are 2 moles of Fe per 1 mole of Fe2O3):
Moles of Fe = Moles of Fe2O3 * (2 / 1)
Now, let's plug in the values into the equations:
Moles of Fe2O3 = 21.3g / 159.6 g/mol
Moles of Fe = (21.3g / 159.6 g/mol) * (2 / 1)
Now you can do the math to find the moles of Fe.