Bạn tham khảo:
$a/$
$K_2O+H_2O \to 2KOH$
$n_{K_2O}=0,05(mol)$
$b/$
$n_{KOH}=0,05.2=0,1(mol)$
$CM_{KOH}=\frac{0,1}{0,02}=5M$
$c/$
$KOH+HCl \to KCl+H_2O$
$n_{HCl}=n_{KOH}=0,1(mol)$
$m_{ddHCl}=\frac{0,1.36,5.100}{20}=18,25(g)$
V_{HCl}=\frac{18,25}{0,9125}=20(ml)
$d/$
$n_{KCl}=0,1(mol)$
$CM_{HCl}=\frac{0,1}{0,02}=5M$