\(PTHH:Cu+4HNO_{3\left(đ\right)}\rightarrow Cu\left(NO_3\right)_2+2NO_2\uparrow+2H_2O\\ n_{Cu}=\dfrac{6,4}{64}=0,1\left(mol\right)\\ \Rightarrow\left\{{}\begin{matrix}n_{NO_2}=0,2\left(mol\right)\\n_{Cu\left(NO_3\right)_2}=0,1\left(mol\right)\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}V=V_{NO_2}=0,2\cdot22,4=4,48\left(l\right)\\m=m_{Cu\left(NO_3\right)_2}=0,1\cdot188=18,8\left(g\right)\end{matrix}\right.\)