Răspuns:
Explicație:
2Na + 2H2O=2 NaOH + H2
2NaOH + H2SO4= Na2SO4 + 2H2O
2NaOH + CO2= Na2CO3 + H2O
2NaOH+ CuSO4= Na2SO4 + Cu(OH)2
Comp. proc. prin masa moleculara
MNaOH= 23 +16 +1=40--------> 40g/moli
40g NaOH ------23g Na -------16g O--------1g H
100gNaOH----------X-------------------Y---------Z
X= 100 . 23 : 40=57,5% Na
Y= 100 .16 : 40=40% O
Z= 100 .1 : 40=2,5% H
MCu(OH)2= 64 + 2.16 + 2=98------> 98g/moli
98g Cu(OH)2-----------64g Cu-------32g O--------2gH
100--------------------------x-----------------------y-----------z
x=100.64 : 98=65,31% Cu
y= 100.32 :98=32,65% O
z= 100 .2 : 98=2,05%H