In: Chemistry
In the laboratory you dissolve 13.2 g of
iron(III) acetate in a volumetric flask and add
water to a total volume of 500 mL.
What is the molarity of the solution? M.
What is the concentration of the iron(III)
cation? M.
What is the concentration of the acetate
anion? M.
Solution :-
Iron (lll) acetate = Fe(C2H3O2)3 = 232.97 g per mol
Lets first calculate the moles of the iron(III) acetate
Moles = mass / molar mass
Moles of iron(III) acetate = 13.2 g / 232.97 g per mol
= 0.0567 mol
Now lets calculate its molarity
Molarity = moles / volume in liter
Molarity = 0.0567 mol / 0.500 L
= 0.113 M iron(III) acetate
Now lets calculate the concentration of the iron (lll) cation
Mole ratio is 1 : 1
Therefore
0.113 M Fe(C2H3O2)3 * 1 M Fe^3+ / 1 M Fe(C2H3O2)3 = 0.113 M Fe^3+
Threfore the concentration of the Iron (lll) cation is 0.113 M
Now lets calculate the concentration of the acetate ion
Mole ratio is 1 : 3
0.113 M Fe(C2H3O2)3 * 3 M C2H3O2^- / 1 M Fe(C2H3O2)3 = 0.339 M C2H3O2^-
Threfore the concentration of the acetate ion is 0.339 M