Question

URGENT !!! Va rog rezolvati-mi problemele : 1. Aflati masa de sodiu care se gaseste in 248 g de oxid de sodiu ( Na2O ) .
2. Aflati masa de hidroxid de magneziu care corespunde unei mase de 240g de magneziu .
3. Determinati raportul atomic si raportul de masa al elementelor care formeaza hidroxidul de aluminiu .

Answer 1

1. MNa2O=2ANa+AO=2*23+16=62g/mol

62g Na2O...............................2*23=46g Na
248g Na2O...............................xg Na

x=46*248/62= Calculeaza !!

2. MMg=24g/mol

MMg(OH)2=AMg+2(AO+AH)=24+2(16+1)=58g/mol

24g Mg................................58g Mg(OH)2
240g Mg...............................xg Mg(OH)2

x=58*240/24=

3. Al(OH)3 = MAl+3(AO+AH) = 27+3(16+1)=78g/mol

raport masic => 27:48:3=9:16:1

raport atomic => 1:3:3