Initial Mass: 7.53 g NaHCO3

Three potential reactions for this
experiment are:
Reaction I:
NaHCO3(s) → NaOH(s) + CO2(g)

Reaction II:
2NaHCO3(s) → Na2O(s) + 2CO2(g) + H2O(g)

Reaction III:
2NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)

Using the experimental data, what
mass of the solid product, Na₂O,
should remain for Reaction II?

2.78 g Na₂O
4.75 g Na₂O
3.59 g Na₂O