2NaOH+H2SO4=Na2SO4+2H2O
2 1
m(NaOH)=150*0,2=30г; n(NaOH)= 30:40=0,75моль; n(Na2SO4)= 0,75 :2=0,375моль;
m(Na2SO4)теоретическая =0,375*142=53,25г;
m(Na2SO4)практическая =53,25*0,9=47,925г.
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