Răspuns:
Explicație:
800g NaOH
react. cu H2SO4
randam. = 80%
masa de produsi de reactie
randament= mp .100 : mt
mp= mt . randam : 100
mp= 800 . 80 : 100= 640g NaOH (care react.)
640g xg yg
2NaOH + H2SO4= Na2SO4 + 2H2O
2. 40g 142g 2.18g
x= 640 . 142 : 80 = 1136 g Na2 SO4
n= m : M
M= 2.23 + 32 + 4.16=142----> 142g/moli
n= 1136g : 142g/moli = 8 moli Na2SO4
y= 640. 36 : 80 = 288g H2O
n= 288g : 18g/moli = 16 moli H2O
MNaOH= 23 + 16 +1=40----> 40g/moli