Algorithm for solving the third problem in chemical problems.

Tannic acid belongs to organic matter (because the carbon-containing substance in the compound is organic matter, except for CO and CO2, these two compounds are not organic matter because of their low carbon content. )

The relative molecular weight of tannic acid is 1700. ( 12*76+52* 1+46* 16= 1700)

The hydrogen-containing element is 5.2g (the relative molecular weight of hydrogen is (52/1700) *100% = (13/425)%, because there is tannic acid in 170g, so: (/kloc-0)