Nhầm Cu,Zn,Fe mới đúng
Cu ko tác dụng vs dd axit loãng
3Zn+8HNO3----->3Zn(NO3)2+2NO+4H2O(1)
Fe+4HNO3---->Fe(NO3)3+NO+2H2O(2)
n \(_{NO}=\frac{6,72}{22,4}=0,3\left(mol\right)\)--->m NO=0,3.30=9(g)
Theo pthh
n\(_{HNO3}=4n_{NO}=1,2\left(mol\right)\)
m\(_{HNO3}=1,2.63=75,6\left(g\right)\)
m muối khan=m KL+m axit-m Khí
=2,3+75,6-9=68,9(g)
\(\text{Ta có }:nNO=0,3\left(mol\right)\Rightarrow mNO=0,3.30=9\left(g\right)\)
\(PTHH:3Zn+3HNO3\rightarrow3Zn\left(NO3\right)2+2NO+4H2O\)
\(Fe+4HNO3\rightarrow Fe\left(NO3\right)3+NO+2H2O\)
\(\text{Từ PTHH:}nHNO3=1,2\left(mol\right)\Rightarrow mHNO3=1,2.63=75,6\)
\(\Rightarrow\text{Tự tính nhé}\)