Answer:
phenolphthalein
Explanation:
In the titration of strong acid and strong base, phenolphthalein is used as suitable indicator.
6.02 x 10²⁴ molecules of C2H6O
First let us convert the
mass of Fe2O3 to moles by dividing the mass of Fe2O3 by its molecular mass,
159.69 g/mol.
moles Fe2O3 = 18.7 /
159.69 = 0.117 mol<span>
<span>Then we know that there are 2 moles of Fe for every 1 mole of
Fe2O3. So,</span></span>
moles Fe = 2 * 0.117 mol
= 0.234 mol
Now to make Fe3O4
requires 3 moles of Fe, therefore:
moles Fe3O4 = 0.234 mol
(1 / 3) = 0.078 mol
Converting to mass by
multiplying with the molar mass of Fe3O4, 231.533 g/mol:
<span>mass Fe3O4 = 0.078 mol * 231.533 g / mol = 18.08 g
answer:18.08 g</span>