a) PTHH: \(K_2O+H_2O\rightarrow2KOH\)
Ta có: \(n_{K_2O}=\frac{4,7}{94}=0,05\left(mol\right)\) \(\Rightarrow n_{KOH}=0,1mol\)
\(\Rightarrow M_{KOH}=\frac{0,1}{0,5}=0,2\left(M\right)\)
b) PTHH: \(KOH+HCl\rightarrow KCl+H_2O\)
Theo PTHH: \(n_{KOH}=n_{HCl}=0,1mol\)
\(\Rightarrow V_{ddHCl}=\frac{0,1}{1}=0,1\left(l\right)=100\left(ml\right)\)