An ore contains Fe3O4 and no other iron. The
iron in a 51.98 gram sample of the ore is all
converted by a series of chemical reactions to
Fe2O3. The mass of Fe2O3 is measured to be
32.8 grams. What was the percent Fe3O4 in
the sample of ore?
Answer in units of %.
The easy way to do it is as follows:
32.8g x (2*molar mass Fe3O4/3*molar mass Fe2O3) = g Fe3O4.
Then (g Fe3O4/51.98)*100 = %Fe3O4
To find the percent Fe3O4 in the sample of ore, we need to calculate the mass of Fe3O4 and then determine what percentage it is of the total sample weight.
Let's break down the steps to solve the problem:
Step 1: Calculate the molar mass of Fe3O4.
The molar mass of Fe3O4 can be calculated by summing the molar masses of iron (Fe) and oxygen (O):
Molar mass of Fe3O4 = (3 * Molar mass of Fe) + (4 * Molar mass of O)
The molar mass of iron (Fe) is 55.845 g/mol, and the molar mass of oxygen (O) is 15.999 g/mol. By substituting these values into the formula, we can calculate the molar mass of Fe3O4.
Step 2: Calculate the number of moles of Fe3O4.
To find the number of moles, we divide the mass of Fe3O4 by its molar mass:
Number of moles = Mass of Fe3O4 / Molar mass of Fe3O4
Step 3: Calculate the number of moles of Fe2O3.
Since the entire amount of iron in the sample is converted to Fe2O3, the number of moles of Fe2O3 is the same as the number of moles of Fe3O4.
Step 4: Calculate the mass of Fe3O4 in the sample.
To find the mass of Fe3O4, we multiply the number of moles of Fe3O4 by its molar mass:
Mass of Fe3O4 = Number of moles of Fe3O4 * Molar mass of Fe3O4
Step 5: Calculate the percent Fe3O4.
The percent Fe3O4 is determined by dividing the mass of Fe3O4 by the total sample weight and multiplying by 100:
Percent Fe3O4 = (Mass of Fe3O4 / Total sample weight) * 100
By following these steps, we can solve the problem and find the percent Fe3O4 in the sample of ore.