The mass percent of NaHCO3 can be calculated by dividing the mass of NaHCO3 by the total mass of the compound and then multiplying the quotient by 100 to get the percentage.
mass % of NaHCO3 = (mass of NaHCO3 / total mass) * 100
Now, we have:
mass of NaHCO3 = 1916 mg
total mass = 325 + 1000 + 1916 = 3241 mg
Substitute with these numbers in the equation to get the mass percentage as follows:
mass % = (1916/3241) * 100 = 59.11755631%