Question

Calculează cantitatea de zinc, respectiv de hidroxid de sodiu, care reacționeaza cu 18,069 × 10 la puterea 23 molecule de acid sulfuric. Determina numarul total de săruri formate.

Answer 1

1mol..............6.022*10^23 molecule
x=3mol.................18.069*10^23 molecule
Zn + H2SO4 => ZnSO4 + H2
nZn=nH2SO4
MZn=65g/mol
m=3*65=195gZn
2NaOH + H2SO4 => Na2SO4 + 2H2O
2mol NaOH.......1mol H2SO4
x=6mol............3mol H2SO4
MNaOH=40g/mol
m=6*40=240g NaOH
Nr săruri = 2 (Na2SO4+ZnSO4)

Answer 2

Zn + H2SO4 = ZnSO4 + H2
2 NaOH + H2SO4 = Na2SO4 + 2 H2O
1 mol H2SO4 ............ 6,023 * 10 la 23 molecule 
x moli H2SO4...............18,069 * 10 la 23 molecule
x = 3 moli H2SO4
1 mol Zn................1 mol H2SO4
x moli Zn...............3 moli H2SO4
x = 3 moli Zn
m zinc = 3*65 = 195 g
2 mol NaOH................1 mol H2SO4
x moli NaOH...............3 moli H2SO4
x = 6 moli NaOH
m hidroxid = 6*40 = 240 g
1 mol Zn................1 mol ZnSO4
3 moli Zn...............x moli ZnSO4
x = 3 moli ZnSO4
m ZnSO4 = 3*161 = 483 g ZnSO4
2 mol NaOH................1 mol Na2SO4
6 moli NaOH...............x moli Na2SO4
x = 3 moli Na2SO4
m Na2SO4 = 3*142 = 426 g Na2SO4
masa saruri totala = 426 + 483 = 909 g