Answer :
Molar mass:
Na₂O = 61.97 g/mol
Na = 22.98 g/mol
4 Na + O₂ = 2 Na₂O
4 x 22.98 g Na ---------- 2 x 61.97 g Na₂O
57.5 g Na ---------------- ??
Mass of Na₂O = 57.5 x 2 x 61.97 / 4 x 22.98
Mass of Na₂O = 7126.55 / 91.92
=> 77.53 g of Na₂O
Na₂O = 61.97 g/mol
Na = 22.98 g/mol
4 Na + O₂ = 2 Na₂O
4 x 22.98 g Na ---------- 2 x 61.97 g Na₂O
57.5 g Na ---------------- ??
Mass of Na₂O = 57.5 x 2 x 61.97 / 4 x 22.98
Mass of Na₂O = 7126.55 / 91.92
=> 77.53 g of Na₂O