Các chất có CTHH sau: K2O; HCl; Fe(OH)2; Fe(OH)3; H2SO4; COCO2; HNO3; H3PO4; FeSO4; Fe2(SO4)3

$\left.\begin{array}{l}{\mathrm{K}}_2:\mathrm{kali}\mathrm{oxit}\\ \mathrm{CO}:\mathrm{cacbon}\left(\mathrm{II}\right)\mathrm{oxit}\\ {\mathrm{CO}}_2:\mathrm{cacbon}\left(\mathrm{IV}\right)\mathrm{oxit}\end{array}\right\}$ loại chất oxit.

$\left.\begin{array}{l}\mathrm{HCl}:\mathrm{axit}\mathrm{clohidric}\\ {\mathrm{HNO}}_3:\mathrm{axit}\mathrm{nitric}\\ {\mathrm{H}}_2{\mathrm{SO}}_4:\mathrm{axit}\mathrm{sunfuric}\\ {\mathrm{H}}_3{\mathrm{PO}}_4:\mathrm{axit}\mathrm{photphoric}\end{array}\right\}$ loại chất axit.

$\left.\begin{array}{l}\mathrm{Fe}{\left(\mathrm{OH}\right)}_2:\mathrm{Sat}\left(\mathrm{II}\right)\mathrm{hidroxit}\\ \mathrm{Fe}{\left(\mathrm{OH}\right)}_3:\mathrm{Sat}\left(\mathrm{III}\right)\mathrm{hidroxit}\end{array}\right\}$ loại chất bazơ.

$\left.\begin{array}{l}{\mathrm{FeSO}}_4:\mathrm{sat}\left(\mathrm{II}\right)\mathrm{sunfat}\\ {\mathrm{Fe}}_2{\left({\mathrm{SO}}_4\right)}_3:\mathrm{sat}\left(\mathrm{III}\right)\mathrm{sunfat}\end{array}\right\}$ loại chất muối.