Đáp án đúng: C
C5H12.
$\displaystyle \begin{array}{l}TH1:{{n}_{C{{O}_{2}}}}\,=\,{{n}_{CaC{{O}_{3}}}}\,=\,0,03\,mol\\{{m}_{\text{dd}\,sau}}\,-\,{{m}_{\text{dd}\,trc}}\,=\,0,28\,=\,{{m}_{C{{O}_{2}}}}\,+\,{{m}_{{{H}_{2}}O}}\,-\,{{m}_{CaC{{O}_{3}}}}\\\Rightarrow \,{{m}_{{{H}_{2}}O}}\,=\,1,96\,gam\,\Rightarrow \,{{n}_{{{H}_{2}}O}}\,=\,0,108\,\\\Rightarrow \,{{n}_{ankan}}\,=\,0,079\,>\,{{n}_{C{{O}_{2}}}}\,\,(L)\end{array}$
$\begin{array}{l}TH2:\,{{n}_{Ca{{(HC{{O}_{3}})}_{2}}}}\,=\,0,04\,-\,0,03\,=\,0,01\,mol\\{{n}_{C{{O}_{2}}}}\,=\,2{{n}_{Ca{{(HC{{O}_{3}})}_{2}}}}\,+\,{{n}_{CaC{{O}_{3}}}}\,=\,0,05\\{{m}_{\text{dd}\,sau}}\,-\,{{m}_{\text{dd}\,trc}}\,=\,0,28\,=\,{{m}_{C{{O}_{2}}}}\,+\,{{m}_{{{H}_{2}}O}}\,-\,{{m}_{CaC{{O}_{3}}}}\\\Rightarrow \,{{m}_{{{H}_{2}}O}}\,=\,1,08gam\,\Rightarrow \,{{n}_{{{H}_{2}}O}}\,=\,0,06\\\Rightarrow \,{{n}_{ankan}}\,=\,0,01\,\Rightarrow \,C\,=\,5\end{array}$
