\(n_{CaCO_3}=\dfrac{20}{100}=0.2\left(mol\right)\)
\(CaCO_3+2HCl\rightarrow CaCl_2+CO_2+H_2O\)
\(0.2.............0.4..........0.2...........0.2........0.2\)
\(m_{HCl}=x=0.4\cdot36.5=14.6\left(g\right)\)
\(m_{CaCl_2}=0.2\cdot111=22.2\left(g\right)\)
Số phân tử H2O : \(0.2\cdot6\cdot10^{23}=1.2\cdot10^{23}\left(pt\right)=z\)
\(m_{CO_2}=m=0.2\cdot44=8.8\left(g\right)\)