Chapter 8, Problem 30P

Interpretation Introduction

Interpretation:

The number of milliequivalent of each of ${\text{Na}}^{+}$ and ${\text{HPO}}_4{}^{2-}$ ions in $\text{320 mL}$ of ringer's solution is to be calculated.

Concept introduction:

The concentration of an ion in solution is expressed in equivalents. One equivalent of an ion can be defined as amount of charge an ion contributes when present in dissolved form. For example, one mole of ${\text{Mg}}^{2+}$ contributes 2 equivalent of ${\text{Mg}}^{2+}$ ions as the charge is $+2$ . Similarly, one mole of ${\text{SO}}_4{}^{2-}$ contributes 2 equivalent of ${\text{SO}}_4{}^{2-}$ ions as the charge is $-2$.

The concentration of an electrolyte is often expressed in $\text{mEq}/\text{L}$ . The conversion factor to convert milliequivalent to equivalent is as follows:

  $1\text{ mEq}={10}^{-3}\text{ eq}$

To convert one system of unit to another the conversion factors are written such that the unwanted units lie in the denominator and thus are canceled out.

The conversion factor to convert $\text{mL}$ to $\text{L}$ is given as follows:

  $1\text{ mL}={\text{10}}^{-3}\text{ L}$