Đáp án:
A
Giải thích các bước giải:
\(\begin{array}{l}
CaC{O_3} + 2HCl \to CaC{l_2} + C{O_2} + {H_2}O(1)\\
NaHC{O_3} + HCl \to NaCl + C{O_2} + {H_2}O(2)\\
C{O_2} + Ba{(OH)_2} \to BaC{O_3} + {H_2}O(3)\\
{n_{BaC{O_3}}} = \dfrac{{19,7}}{{197}} = 0,1\,mol\\
{n_{C{O_2}(3)}} = {n_{BaC{O_3}}} = 0,1\,mol\\
hh:CaC{O_3}(a\,mol),NaHC{O_3}(b\,mol)\\
{n_{CaC{l_2}}} = {n_{CaC{l_2}}} = {n_{C{O_2}(1)}} = a\,mol\\
{n_{NaCl}} = {n_{NaHC{O_3}}} = {n_{C{O_2}(2)}} = b\,mol\\
\Rightarrow {n_{CaC{l_2}}} + {n_{NaCl}} = {n_{C{O_2}(1)}} + {n_{C{O_2}(2)}} = {n_{C{O_3}(3)}} = 0,1\,mol
\end{array}\)
