\(V_{H_2O}=0,1l=100ml\\ \rightarrow m_{H_2O}=100.1=100\left(g\right)\\ n_{HCl}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\\ \rightarrow m_{HCl}=0,25.36,5=9,125\left(g\right)\\ \rightarrow\left\{{}\begin{matrix}C_{M\left(HCl\right)}=\dfrac{0,25}{0,1}=2,5M\\C\%_{HCl}=\dfrac{9,125}{100+9,125}.100\%=8,36\%\end{matrix}\right.\)