Đáp án đúng: B
0,84 lít.
$\displaystyle \begin{array}{l}\text{Cu}\,\text{(0,2}\,\text{mol)}\xrightarrow{\text{+}{{\text{O}}_{\text{2}}}}\left\{ \begin{array}{l}\,\,\,\,\,\text{3Cu}\,\,\,\,\,\text{+}\,\,\,\,\,\,\,\text{8HN}{{\text{O}}_{\text{3}}}\xrightarrow{{}}\text{3Cu(N}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}\text{+}\,\text{2NO}\,\text{+}\,\text{4}{{\text{H}}_{\text{2}}}\text{O}\\\text{0,03}\,\,\text{mol}\,\,\leftarrow \,\,\,\text{0,08}\,\,\,\,\,\,\,\,\xleftarrow{{}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\text{0,02}\,\text{mol}\\\,\,\,\,\,\text{CuO}\,\,\,\,\text{+}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\text{+}\,\,\,\,\,\,\,\text{2HN}{{\text{O}}_{\text{3}}}\xrightarrow{{}}\,\,\text{Cu(N}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}\,\,\text{+}\,\,{{\text{2H}}_{\text{2}}}\text{O}\\\text{(0,2}\,\text{-}\,\text{0,03}\,\text{=}\,\text{0,17}\,\text{mol)}\,\to \,\,\text{0,34}\end{array} \right.\,\\\Rightarrow \,{{\text{n}}_{\text{HN}{{\text{O}}_{\text{3}}}}}\text{=0,42}\,\text{mol}\,\Rightarrow \,{{\text{V}}_{\text{dd}\,\,\text{HN}{{\text{O}}_{\text{3}}}}}\text{=0,84l}\end{array}$
