-se afla md sol. de NaOH
md=c.ms :100
md= 40. 200 :100= 80 g NaOH
- se scrie ec. si se calculeaza cantit. de SO2 [ x]
80g xg
2 NaOH + SO2= Na2SO3 + H2O
2.40g 64g
x=80 . 64 : 2 . 40= 64 g SO2
[n=m: M= 64g : 64g/moli=1moli SO2 ]
MNaOH=23+16+1=40-----> 40g/moli
MSO2=32 + 2.16=64------> 64g/moli