Answer:
CO32−
Explanation:
We have to consider the valencies of the polyatomic ions involved. Recall that it is only a polyatomic ion with a valency of -2 that can form a compound which requires two sodium ions.
When we look closely at the options, we will realize that among all the options, only CO32− has a valency of -2, hence it must be the required answer. In order to be double sure, we put down the ionic reaction equation as follows;
2Na^+(aq) + CO3^2-(aq) ---------> Na2CO3(aq)
Opposing reactions are constantly occurring at equal rates
favoring the formation if fewer miles if gaseous products
a. 48.6 is magnesium and 32.0 is oxygen
b. 80.6
c. also 80.6
d. yes, because the product has equal mass to the reactants
