How many grams of naoh is produced from 1.20 x 102 grams of na2o?

Molecular mass of NaOH = 23.0+16.0+1.00 = 40.0
Molecular mass of Na2O = 2*23.0 = 46.0

Equation of reaction:

Na2O + H2O = 2NaOH

So 1 mole of Na2O will produce 2 moles of NaOH, or
46 grams of Na2O will produce 2*40=80 grams of NaOH.

1.20*10^2 grams = 120 grams

Therefore
120 grams of Na2O will produce
120*80/46 = 208.7 grams of NaOH.

209 grams of NaOH will be produced (to 3 significant figures)

Rara tee da goo boo boo teee gaaa baa baa