Thus problem is providing us with the mass of iron (III) oxide as 12.4 g so the moles are required and found to be 0.0776 mol after the calculations:
<h3>Mole-mass relationships:</h3>
In chemistry, we use mole-mass relationships in order to calculate grams from moles and vice versa. In this case, since we are given the mass of iron (III) oxide as 12.4 g one can calculate the moles by firstly quantifying its molar mass:

Then, we prepare a conversion factor in order to cancel out the grams and thus, get moles:

Learn more about mole-mass relationships: brainly.com/question/18311376
Ok thanks for the valuble info.
Answer:
The second answer, because when something saturated, it has the maximum possible number of hydrogen atoms.
It is beacuse the ions in the melted or aqueous ionic compound is mobile and can freely move through the fluid and conduct electricity.
A bag of soil will weigh in kilograms