Complete this equation for the dissociation of na2co3(aq). omit water from the equation because it is understood to be present.

Note that we are omitting the water.

So, sodium carbonate will basically dissociate into positive sodium ions and negative carbonate ions based on the following equation:
 Na2CO3 → 2 Na(+) + CO3(2-)

If we took water into consideration:
Sodium carbonate will dissociate in water forming carbonic acid and sodium hydroxide. Since sodium hydroxide is a strong base, therefore, it will then neutralize the gastric acid, thus, acting as an antacid.

B? i feel like this is a trick