For the following equation (2naoh+> na2so4+2h2o) what mass of sodium sulfate (in grams) will be produced from 1.85 mold of sodium hydroxide, naoh?

Number of mole (NaOH)= 1.85 mol
Using mole ratio
n(Na2SO4)/n(NaOH)= 1/3
So number of mole of Na2SO4 is the number of mole of NaOH multiplied by 1/3 which equals 0.616 (approx.)
Then to find mass we use
Mass(in grams)= number of mole of compound (Na2SO4) multiplied by the Molar mass of our compound molar mass (Na2SO4) =142.04
m= n X Mr
m= 0.616 x 142.04
=87.59g

The answer is b because a,c,and d are opinons