Răspuns:
12,5g Pb
Explicație:
md = c × ms / 100 = 10 × 200 / 100 = 20g Pb(NO₃)₂
M(Pb(NO₃)₂) = A(Pb) + 2A(N) + 6A(O) = 207 + 2 × 14 + 6 × 16 = 331 g/mol
n(Pb(NO₃)₂) = 20g / 331 g/mol = 0,06 mol
Zn + Pb(NO₃)₂ → Zn(NO₃)₂ + Pb↓
1 mol Pb(NO₃)₂.....1 mol Pb
0,06 mol Pb(NO₃)₂.....x mol Pb
x = 0,06 mol Pb
A(Pb) = 207 g/mol
m(Pb) = 0,06 mol × 207 g/mol ≈ 12,5g
-Mihai