Gọi số mol Zn là a (mol)
\(n_{NO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\); \(n_{NO}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
\(Zn^0-2e\rightarrow Zn^{+2}\)
a----->2a________________(mol)
\(N^{+5}+1e\rightarrow N^{+4}\)
_____0,3<---0,3___________(mol)
\(N^{+5}+3e\rightarrow N^{+2}\)
_____0,3<---0,1___________(mol)
THEO ĐLBT e: 2a = 0,6
=> a = 0,3 (Mol)
=> m = 0,3.65 = 19,5(g)