Question

How manymoles of each ion are present in 175 mL of 0.147 M Fe2(SO4)3?

Answer 1

Answer: 0.0257 moles of $Fe^{3+}$  and 0.0257 moles of $SO_4^{2-}$

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

$Molarity=\frac{moles}{\text {Volume in L}}$

moles of  $Fe_2(SO_4)_3=Molarity\times {\text {Volume in L}}=0.147\times 0.175L=0.0257moles$

The balanced reaction for dissociation will be:

$Fe_2(SO_4)_3\rightarrow Fe^{3+}+SO_4^{2-}$

According to stoichiometry:  

1 mole of $Fe_2(SO_4)_3$ gives 1 mole of $Fe^{3+}$  and 1 mole of $SO_4^{2-}$

Thus there will be 0.0257 moles of $Fe^{3+}$  and 0.0257 moles of $SO_4^{2-}$