Question

Cantitatea de oxid de sodiu obtinuta prin arderea a 69 g sodiu in oxigen se combina cu apa.Afla cantitatea de oxigen necesara in moli si numarul de molecule precum si masa de hidroxid de sodiu obtinuta.

Answer 1

MNa=23g/mol
MO2=32g/mol

n=m/M=69/23=3 moli Na

2Na + 1/2O2 -> Na2O

2 moli Na..............1 mol Na2O
3 moli Na..............x moli Na2O

x=1*3/2=

2 moli Na.............0,5 moli O2
3 moli Na.............x moli O2

x=0,5*3/2 = 

Na2O + H2O => 2NaOH

1 mol Na2O...............2*40g NaOH
1,5 moli Na2O...............xg NaOH

x=80*1,5=120g NaOH

n=m/M=120/40=3 moli NaOH

1 mol NaOH....................6,023*10^23 molecule
3 moli NaOH.....................x molecule

x=18,069*10^23 molecule NaOH