Answer: The molecular equation is written below.
Step-by-step explanation:
A molecular equation is defined as the balanced chemical equation where the ionic compounds are expressed as molecules rather than constituent ions.
The balanced chemical equation for the reaction of sodium sulfate and barium nitrate follows:

By Stoichiometry of the reaction:
1 mole of sodium sulfate reacts with 1 mole of barium nitrate to produce 2 moles of sodium nitrate and 1 mole of barium sulfate.
Hence, the molecular equation is written above.