Giả sử có 100 (g) dd HCl 32,85%
\(n_{HCl\left(bđ\right)}=\dfrac{100.32,85\%}{36,5}=0,9\left(mol\right)\)
Gọi số mol CaCO3 là a (mol)
PTHH: \(CaCO_3+2HCl\rightarrow CaCl_2+CO_2+H_2O\)
a------->2a-------->a----->a
=> mdd X = 100a + 100 - 44a = 100 + 56a (g)
nHCl(X) = 0,9 - 2a (mol)
\(C\%_{HCl\left(X\right)}=\dfrac{36,5\left(0,9-2a\right)}{100+56a}.100\%=24,195\%\)
=> a = 0,1 (mol)
mdd X = 105,6 (g)
nHCl(X) = 0,7 (mol)
Gọi số mol MgCO3 là b (mol)
PTHH: \(MgCO_3+2HCl\rightarrow MgCl_2+CO_2+H_2O\)
b-------->2b------->b------->b
mdd Y = 105,6 + 84b - 44b = 105,6 + 40b (g)
nHCl(Y) = 0,7 - 2b (mol)
\(C\%_{HCl\left(Y\right)}=\dfrac{\left(0,7-2b\right).36,5}{105,6+40b}.100\%=21,11\%\)
=> b = 0,04 (mol)
dd Y chứa \(\left\{{}\begin{matrix}CaCl_2:0,1\left(mol\right)\\MgCl_2:0,04\left(mol\right)\end{matrix}\right.\)
mdd Y = 107,2 (g)
\(\left\{{}\begin{matrix}C\%_{CaCl_2}=\dfrac{0,1.111}{107,2}.100\%=10,35\%\\C\%_{MgCl_2}=\dfrac{0,04.95}{107,2}.100\%=3,54\%\end{matrix}\right.\)