\(n_{NO2}=\frac{0,72}{22,4}=\frac{9}{280}\left(mol\right)\)
Cu + 4HNO3 → Cu(NO3)2 + 2NO2 + 2H2O
\(\frac{9}{560}\)___\(\frac{9}{140}\)_________________\(\frac{9}{280}\)_________(mol)
\(m_{Cu}=\frac{9}{560}.64=1.03g\)
\(CM_{HNO3}=\frac{\frac{9}{140}}{0,8}=0,08M\)