Đáp án đúng: B 5,84 $\xrightarrow{\text{BT:}\,\text{e}}\text{3}{{\text{n}}_{\text{Al}}}\,\text{+}\,{{\text{n}}_{\text{Na}}}\text{=}\,\text{2}{{\text{n}}_{{{\text{H}}_{\text{2}}}}}\Rightarrow \text{3x}\,\text{+}\,\text{2x}\,\text{=}\,\text{0,4}\Rightarrow \text{x}\,\text{=}\,\text{0,08}\Rightarrow \text{m}\,\text{=}\,\text{27}{{\text{n}}_{\text{Al}}}\,\text{+}\,\text{23}{{\text{n}}_{\text{Na}}}\text{=}\,\text{5,84}\,\text{gam}$
