Question

Trung hòa 20ml dd H2SO4 1M bằng dd NaOH 20%

a. Viết PTHH

b. Tính khối lượng dd NaOH can dùng

c. Nếu trung hòa dd H2SO4 trên bang dd KOH 5.6% ( D= 1.045g/ml) thì cân bao nhiêu ml dung dịch KOH

Answer 1

\(n_{H2SO4}=0,02.1=0,02\left(mol\right)\)

PTHH: \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)

pư..............0,02..........0,04..............0,02...........0,04 (mol)

\(\Rightarrow m_{NaOH}=0,04.40=1,6\left(g\right)\)

\(\Rightarrow m_{ddNaOH\left(20\%\right)}=\dfrac{1,6}{20\%}=8\left(g\right)\)

PTHH: \(H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\)

pư............0,02............0,04............0,02..........0,04 (mol)

\(\Rightarrow m_{KOH}=0,04.56=2,24\left(g\right)\)

\(\Rightarrow m_{ddKOH\left(5,6\%\right)}=\dfrac{2,24}{5,6\%}=40\left(g\right)\)

\(\Rightarrow V_{KOH}=\dfrac{40}{1,045}\approx38,28\left(ml\right)\)

Vậy..............