Câu 21:

Muối:

$\rm K_3PO_4:Tripotassium\ phosphate$

Acid:

$\rm H_3PO_4:Acid\ phosphoric$

Oxide acid:

$\rm P_2O_5: Phosphor\ pentoxide$

Base:

$\rm KOH: Potassium\ hydroxide$

Câu 22:

$\rm n_{KClO_3}=\dfrac{4,9}{122,5}=0,04\ (mol)\\n_{KCl\ (tt)}=\dfrac{2,086}{74,5}=0,028\ (mol)$

Phương trình phản ứng:

$\rm 2KClO_3\xrightarrow{MnO_2,\ t^°}2KCl+3O_2$

Theo phương trình:

$\rm n_{KCl\ (lt)}=n_{KClO_3}=0,04\ (mol)$

$\rm H=\dfrac{0,028}{0,04}×100\%=70\%$

$\rm b)$

Theo phương trình:

$\rm n_{O_2}=\dfrac{3}{2}n_{KCl\ (tt)}=0,042\ (mol)$

$\rm V_{O_2}=0,042×22,4=0,9408\ (L)$