A 28 g sample 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 19.5 g. What
was the mass of iron in the sample of ore?
Answer in units of g.
2Fe(ore) + ???? ==> Fe2O3 + other stuff.
mass Fe2O3 = 19.5. Convert to moles Fe2O3.
19.5/160 = 0.122 moles.
moles Fe is 0.122 x 2 (there are two moles Fe for every 1 mole Fe2O3) = 0.244 moles Fe.
g Fe = moles x molar mass.
I estimated the molar mass of Fe2O3. You should back track and do that more more exacting than I.
To find the mass of iron in the sample of ore, we can use the fact that all of the iron in the sample is converted to Fe2O3.
We start with a sample of iron ore weighing 28 g.
Since all of the iron in the sample is converted to Fe2O3, the mass of Fe2O3 is 19.5 g.
The molar mass of Fe2O3 is 159.69 g/mol.
To find the moles of Fe2O3, we can divide the mass of Fe2O3 by its molar mass:
moles of Fe2O3 = mass of Fe2O3 / molar mass of Fe2O3
= 19.5 g / 159.69 g/mol
= 0.122 moles
Now, since the stoichiometry of the reaction tells us that 1 mole of Fe2O3 contains 2 moles of Fe, we can calculate the moles of Fe:
moles of Fe = 0.122 moles of Fe2O3 * (2 moles of Fe / 1 mole of Fe2O3)
= 0.244 moles
Finally, to find the mass of iron in the sample, we multiply the moles of Fe by its molar mass:
mass of Fe = moles of Fe * molar mass of Fe
= 0.244 moles * 55.845 g/mol
= 13.64 g
Therefore, the mass of iron in the sample of ore is approximately 13.64 g.
To find the mass of iron in the sample of ore, we need to calculate the mass difference between the initial sample of iron ore and the final mass of Fe2O3. Here's how to do it step by step:
1. Find the mass of iron ore:
The initial mass of the iron ore sample is given as 28 g.
2. Find the mass of Fe2O3:
The mass of Fe2O3 after the chemical reactions is measured as 19.5 g.
3. Calculate the mass of iron in the sample:
The difference between the initial mass of the iron ore sample and the final mass of Fe2O3 will give us the mass of iron in the sample.
Mass of iron = Initial mass of iron ore - Mass of Fe2O3
Mass of iron = 28 g - 19.5 g
= 8.5 g
Therefore, the mass of iron in the sample of ore is 8.5 grams.