\(1,n_{H^+}=n_{Cl^-}=n_{HCl}=0,2\left(mol\right)\\2,n_{Ba^{2+}}=n_{Ba\left(OH\right)_2}=0,25\left(mol\right)\\ n_{OH^-}=2.0,25=0,5\left(mol\right)\\ 3,n_{H^+}=0,1.2=0,2\left(mol\right)\\ n_{SO_4^{2-}}=0,1\left(mol\right)\\ n_{Na^+}=n_{OH^-}=n_{NaOH}=0,15\left(mol\right) \)