Question

1.Cate grame de oxid de aluminiu se obtin prin arderea a 270 g aluminiu?
2. 195 g zinc reactioneaza cu o acidul clorhidric. Calculati
Masa de clorura de zinc obținuta
Nr de molo molecule litri de hidrogem rezultati

Answer 1

1. 2Al + 3O2 => Al2O3

MAl=27g/mol

MAl2O3=2AAl+3AO=2*27+3*16=102g/mol

n=m/M=270/27=10 moli Al

2 moli Al.............102g Al2O3
10 moli Al...........xg Al2O3

x=102*10/2= Calculează !!

2. MZn=65g/mol

MZnCl2=136g/mol

n=m/M=195/65=3 moli Zn

Zn + 2HCl -> ZnCl2 + H2

1 mol Zn.........136g ZnCl2
3 moli Zn........xg

x=136*3=


1 mol Zn.............22,4 L H2
3 moli Zn............x L H2

x=22,4*3=



nZn=nH2= 3 moli H2

1 mol H2...........NA=6.023*10^23 molecule
3 moli H2.........x molecule

x=6.023*10^23*3=