Question

Answer 1

Bài 5:

Ta có: \(n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\)

a, PT: \(Na_2O+H_2O\rightarrow2NaOH\)

_______0,25____________0,5 (mol)

\(\Rightarrow C_{M_{NaOH}}=\dfrac{0,5}{0,5}=1M\)

b, \(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)

____0,5_______0,25_______0,25 (mol)

\(\Rightarrow m_{H_2SO_4}=0,25.98=24,5\left(g\right)\)

\(\Rightarrow m_{ddH_2SO_4}=\dfrac{24,5}{20\%}=122,5\left(g\right)\)

\(\Rightarrow V_{ddH_2SO_4}=\dfrac{122,5}{1,14}\approx107,46\left(ml\right)\)

c, Có: V _{dd sau pư} = V _{dd NaOH} + V _{dd H2SO4} ≃ 0,61 (l)

\(\Rightarrow C_{M_{Na_2SO_4}}=\dfrac{0,25}{0,61}\approx0,41M\)

Bạn tham khảo nhé!