Verified Answer :

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 232
= 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.