Răspuns:
Explicație:
MNaOH= 23 + 16 +1=40-----> 40g/moli
-se afla masa de NaOH din 12 moli de NaOH
m= n . M
m= 12moli. 40g/moli=480g NaOH
-se afla masa de H din 480 g NaOH
40g NaOH ----------1g H
480g --------------------xg
x= 480 : 40= 12 g H
MH3PO4= 3+ 31 + 4.16=98------>98g/moli
m= 4moli.98g/moli=392g H3PO4
98g H3PO4------------3g H
392 g------------------------y
y= 392 . 3 : 98=12 g H
n= 12g :2g/moli=6 moli H2
