5 moles because molarity signifies number of moles dissolved in One litre of water
To calculate this, we need the Molarity formula. This formula tell us that Molarity, which is a concentration unit, is equal to the number of moles divided by the volume. In this question we already have the Molarity and the Volume, so let's build our equation:
C = n/V (You can see Molarity with the letter "C" because it means concentration)
3 = n/1
n = 1 * 3
n = 3 moles of NaOH
Yes they do if that was your question
Answer:

Explanation:
According to the Law of Conservation of Mass, the mass of the products must equal the mass of the reactants.
- mass products = mass reactants
In this problem, the reaction is:

- The reactants are iron and oxygen. We know the mass of the iron sample is 10 grams.
- The product is ferric oxide. The mass of the ferric oxide sample is 18.2 grams.

We want to find how many grams of oxygen reacted. We have to get the oxygen by itself. 10 is being added to oxygen. The inverse of addition is subtraction. Subtract 10 from both sides of the equation.



<u>8.2 grams of oxygen </u>reacted with 10 grams of iron to form 18.2 grams of ferric oxide.