# What is the ionic formula for sodium carbonate?

Well you got the salt of sodium ion...$N {a}^{+}$...
and carbonate ion, $C {O}_{3}^{2 -}$ ion....and clearly the salt is a NEUTRAL species... And so we take two cations, and ONE anion to give us....
$N {a}_{2} C {O}_{3}$ as the $\text{NEUTRAL SALT}$.....and carbonates are labile to acids according to the following equation....
$N {a}_{2} C {O}_{3} \left(a q\right) + 2 H C l \left(a q\right) \rightarrow 2 N a C l \left(a q\right) + C {O}_{2} \left(g\right) \uparrow + {H}_{2} O \left(l\right)$