Hướng dẫn:

${{n}_{{{O}_{2}}}}=\frac{{{V}_{{{O}_{2}}}}}{22,4}=\frac{5,6}{22,4}=0,25\left( mol \right)$

$C+{{O}_{2}}\xrightarrow{{{t}^{0}}}C{{O}_{2}}$

      0,25$\to $  0,25          (mol)

Theo phương trình ta có:

${{n}_{C{{O}_{2}}}}={{n}_{{{O}_{2}}}}=0,25\left( mol \right)$

$\Rightarrow {{V}_{C{{O}_{2}}}}=22,4.{{n}_{C{{O}_{2}}}}=22,4.0,25=5,6\left( l \right)$

$\Rightarrow $Chọn đáp án B