# Question 556c5

Dec 5, 2015

$\text{1.2 Eq}$

#### Explanation:

For an ion, the number of equivalents you get is equal to the number of moles of that ion multiplied by its valence.

$\textcolor{b l u e}{\text{Eq" = "moles" xx "valence}}$

As you know, magnesium is located in group 2 of the periodic table, which means that it has a valence of $2$. As a result, magnesium forms $\left(2 +\right)$ cations, ${\text{Mg}}^{2 +}$.

So, if your solution contains $0.60$ moles of magnesium cations, you can say it contains

"0.60 moles" * 2 = color(green)("1.2 Eq")#

As an interesting practice example, magnesium chloride, ${\text{MgCl}}_{2}$, is a soluble salt that dissociates completely in aqueous solution to give

${\text{MgCl"_text(2(aq]) -> "Mg"_text((Aq])^(2+) + color(red)(2)"Cl}}_{\textrm{\left(a q\right]}}^{-}$

Notice that every mole of magnesium chloride will produce one mole of magnesium cations and $\textcolor{red}{2}$ moles of chloride anions.

This means that the solution will contain $1.20$ moles of chloride anions.

Now, in every aqueous solution, the total number of equivalents of anions must be equal to the total number of equivalents of cations.

In this case, the number of equivalents of chloride anions will be

$\text{1.20 moles" * 1 = "1.2 Eq}$