\(PTHH:\text{Fe+4HNO3}\rightarrow\text{Fe(NO3)3+NO+2H2O}\)
\(\text{3Cu+8HNO3}\rightarrow\text{3Cu(NO3)2+2NO+4H2O}\)
Ta có hh gồm Fe( a mol) Cu(b mol)
\(\Rightarrow\left\{{}\begin{matrix}\text{56a+64b=4,72}\\\text{a+2b/3=0,07}\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}\text{a=0,05}\\\text{b=0,03}\end{matrix}\right.\)
mdd HNO3=(0,05x4+0,03x8/3)x63/20%=88,2(g)
mdd spu=4,72+88,2-0,07x28=90,96(g)
\(\Rightarrow\left\{{}\begin{matrix}\text{C%Fe(NO3)3=13,3%}\\\text{C%Cu(NO3)2=6,2%}\end{matrix}\right.\)
