Chapter 4, Problem 4.35P

Interpretation Introduction

Interpretation:

The moles of ${\text{Na}}^{+}$ ions required to replace $0.015M{\text{ Ca}}^{2+}$ and $0.0010M{\text{ Fe}}^{3+}$ in $1.0\times {10}^3\text{ L}$ of hard water is to be calculated.

Concept introduction:

Molarity $\left(M\right)$ is one of the concentration terms that determine the number of moles of solute present in per liter of solution. Unit of molarity is $\text{mol/L}$.

The expression to calculate the moles of the compound when molarity of solution and volume of solution are given is as follows:

$\text{Moles of compound}\left(\text{mol}\right)=\left[\begin{array}{c}\text{volume of solution}\left(\text{L}\right)\\ \left(\frac{\text{molarity}\text{of}\text{solution}\left(\text{mol}\right)}{\text{1L of solution}}\right)\end{array}\right]$

The expression to calculate the moles of charge from an ion when moles of ion and mole of charge on ion are given is as follows:

$\text{Moles of charge from ion}\left(\text{mol}\right)=\left[\begin{array}{l}\text{moles of ion}\left(\text{mol}\right)\\ \left(\frac{\text{mole of charge on ion}\left(\text{mol}\right)}{\text{1}\text{mol of ion}\left(\text{mol}\right)}\right)\end{array}\right]$