a, Ta có: \(m_{NaOH}=200.4\%=8\left(g\right)\) \(\Rightarrow n_{NaOH}=\dfrac{8}{40}=0,2\left(mol\right)\)
PT: \(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)
_____0,2______0,1_______0,1 (mol)
\(\Rightarrow V_{ddH_2SO_4}=\dfrac{0,1}{0,2}=0,5M\)
b, Ta có: m dd sau pư = m dd NaOH + m ddH2SO4 = 200 + 50 = 250 (g)
\(\Rightarrow C\%_{Na_2SO_4}=\dfrac{0,1.142}{250}.100\%=5,68\%\)
Bạn tham khảo nhé!