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
Answer:
We can't see the options so we don't know what we can put
Explanation:
The arrow doesn’t “point” to anything really, it means that the reactants form (or change) into the products.
1. <span>Substances in a </span>mixture<span> can be separated using different </span>methods, for example <span>distillation (separation of two liquids).
2. </span>Mass<span> is the amount of matter an object contains.
</span>Volume is t<span>he amount of space occupied by a three-dimensional object.
3. d(wallet) = 15g</span>÷5cm³ = 3g/cm³.
4. Weight of an astronaut also increases. W=m·g.