a, Gọi: \(\left\{{}\begin{matrix}n_{Ca\left(OH\right)_2}=x\left(mol\right)\\n_{KOH}=y\left(mol\right)\end{matrix}\right.\) ⇒ 74x + 56y = 7,62 (1)
PT: \(Ca\left(OH\right)_2+2HCl\rightarrow CaCl_2+2H_2O\)
\(KOH+HCl\rightarrow KCl+H_2O\)
Theo PT: \(n_{HCl}=2n_{Ca\left(OH\right)_2}+n_{KOH}=2x+y=\dfrac{31,025.30\%}{36,5}=0,17\left(mol\right)\left(2\right)\)
Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}x=0,05\left(mol\right)\\y=0,07\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Ca\left(OH\right)_2}=0,05.74=3,7\left(g\right)\\m_{KOH}=0,07.56=3,92\left(g\right)\end{matrix}\right.\)
b, \(V_{ddHCl}=\dfrac{31,025}{1,04}\approx29,83\left(ml\right)=0,02983\left(l\right)\)
\(\Rightarrow C_{M_{HCl}}=\dfrac{0,17}{0,02983}\approx5,7\left(M\right)\)