Thank you for the opportunity to help you with your question!
The equation is HCO3 – (aq) +
H^+ (aq) → H2O (l) + CO2 (g)
According to the balanced
chemical equation, it takes one mole of NaHCO3 to produce one mole of CO2.
As a result, mass of NaHCO3 reacted = (mass of CO2 evolved / M.W. of
CO2) × M.W. of NaHCO3
NaHCO3 reacted =(0.883g/44)x84=1.686g
The number of moles of NaHCO3 that reacted= mass of NaHCO3 reacted
moles of NaHCO3 that reacted=1.686g/84=0.02007 moles
Note: Are you sure about the data? There is a difference between weight loss from the formula weight loss= initial mass-final mass=118.021g-117.318g= 0.703g (which is the mass
of CO2) and your data. I used: Mass of Co2 evolved was 0.883g, moles of CO2 evolved was 0.02006g/moles to do the calculations.Please let me know if you need any clarification. I'm always happy to answer your questions.