# What is the total number of ions present in the formula Na2SO4?

## A. 2 B. 3 C. 4 D. 6 The answer given is B. 3, why?

Feb 17, 2016

The answer should be 3 ions.

#### Explanation:

After looking again it seems to me that the number of ions in one molecule are actually just Na, S and O, which means 3 ions.
$\textcolor{red}{\text{What you mentioned Na, S and O are three elements in the}}$ $\textcolor{red}{\text{given compound.}}$
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.

Given compound is ${\text{Na"_2"SO}}_{4}$
If one breaks up the given compound in its constituent ions one obtains
$2 {\text{ cations of sodium, Na}}^{+}$ and $1 {\text{ anion as sulfate, SO}}_{4}^{2 -}$

$\therefore$Total 3 ions.

Feb 17, 2016

$N {a}_{2} S {O}_{4} \to 2 N {a}^{+} + S {O}_{4}^{2} -$