A 40.3 g of iron ore is treated as follows. The iron in the sample is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 10.5 grams. What was the percent iron in the sample of ore?
Answer in units of %
Isn't this done the same as the problems before? Try it yourself first.
Given:
m{sample} = 40.3g
m{Fe2O3} = 10.5g
w{Fe2O3} = 159.6887 ± 0.0002 g/mol
w{Fe} = 55.8452 ± 0.0001 g/mol
And the stoichiometry:
m{Fe}/w{Fe} = 3 m{Fe2O3}/w{Fe2O3}
The percentage of iron in the sample is:
m{Fe}/m{sample} = ...
Typo correction:
m{Fe}/w{Fe} = 2 m{Fe2O3}/w{Fe2O3}
Find the number of moles of Fe2O3 in 10.5g of Fe2O3:
10.5g*(1 mole/159.6882 g)=moles of Fe2O3
Convert moles of Fe2O3 into moles of Fe:
Moles of Fe2O3*(2 moles of Fe/1 mole of Fe2O3)=moles of Fe
How many g of Fe are in the moles of Fe calculated above?
Moles of Fe*(55.845g/1mole)=mass of Fe
(mass of Fe/40.3g of Fe ore)*100=% of Fe in original sample
To find the percent of iron in the sample of ore, we need to calculate the mass of iron and then divide it by the total mass of the sample, and finally multiply by 100 to get the percentage.
Given:
Mass of the iron ore sample = 40.3 g
Mass of Fe2O3 = 10.5 g
Step 1: Calculate the mass of iron in Fe2O3.
To find the mass of iron, we need to determine the molar ratio between iron and Fe2O3. From the chemical formula of Fe2O3, we can observe that there are two iron atoms (Fe) for every one Fe2O3. Since the molar mass of Fe2O3 is 159.69 g/mol, we can calculate the molar mass of iron (Fe) as follows:
Molar mass of Fe2O3 = (2 * molar mass of Fe) + (3 * molar mass of O)
159.69 g/mol = (2 * molar mass of Fe) + (3 * 16.00 g/mol)
159.69 g/mol = 2 * molar mass of Fe + 48.00 g/mol
111.69 g/mol = 2 * molar mass of Fe
molar mass of Fe = 111.69 g/mol / 2
molar mass of Fe = 55.84 g/mol
Now we need to calculate the mass of iron (Fe) in Fe2O3:
Mass of iron (Fe) = (molar mass of Fe / molar mass of Fe2O3) * mass of Fe2O3
Mass of iron (Fe) = (55.84 g/mol / 159.69 g/mol) * 10.5 g
Mass of iron (Fe) = 3.0914 g
Step 2: Calculate the percentage of iron in the sample.
Percentage of iron = (mass of iron / mass of sample) * 100
Percentage of iron = (3.0914 g / 40.3 g) * 100
Percentage of iron ≈ 7.67 %
Therefore, the percent of iron in the sample of ore is approximately 7.67%.