a)\(Na2CO3+2HCl-->2NaCl+H2O+CO2\)
\(CaCO3+2HCl-->CaCl2+H2O+CO2\)
\(K2CO3+2HCl-->2KCl+H2O+CO2\)
b)\(n_{CO2}=\frac{7,84}{22,4}=0,35\left(mol\right)\)
\(\Rightarrow m_{CO2}=0,35.44=15,4\left(g\right)\)
\(n_{H2O}=n_{CO2}=0,35\left(mol\right)\)
\(\Rightarrow m_{H2O}=0,35.18=6,3\left(g\right)\)
\(n_{HCl}=2n_{CO2}=0,7\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,7.36,5=25,55\left(g\right)\)
\(m_{muối}=m_{KL}+m_{HCl}-m_{H2O}-m_{CO2}\)
\(=41,3+25,55-6,3-15,4=45,15\left(g\right)\)