4Na+O2->2Na2O
Given: 95.7gNa
Unknown: ?gNa2O
Plan: gNa to molNa to molNa2O to gNa2O
Relationships: Na ≈ 23 g/mol and O ≈ 16 g/mol;
Na2O has 2 Na and 1 O so 23*2 = 46+16 = 62 g/molNa2O
Solve: 95.7 gNa * 1 molNa/23 gNa * 2molNa2O/4molNa * 62gNa2O/1molNa2O ≈ 128.99gNa2O
My work might be wrong so please check.