Hướng dẫn giải

- PTHH:          ${{H}_{2}}S{{O}_{4}}$ +  $Ca{{(HC{{O}_{3}})}_{2}}$  $\xrightarrow{{}}$  $CaS{{O}_{4}}\downarrow $ +  2$\text{C}{{\text{O}}_{2}}\uparrow $ +  2${{H}_{2}}O$

           ${{K}_{2}}C{{O}_{3}}$  +  2HCl   $\xrightarrow{{}}$  2KCl  +  $\text{C}{{\text{O}}_{2}}\uparrow $ +  ${{H}_{2}}O$

                        2KOH   +   2$NaHC{{O}_{3}}$  $\xrightarrow{{}}$  ${{K}_{2}}C{{O}_{3}}$  +  $N{{a}_{2}}C{{O}_{3}}$  +  2${{H}_{2}}O$

Chọn đáp án A.