The reversible reaction, 4HCl(g) + Si (s) ⇌ SiCl4 (l) + 2H2 (g) , would be classified as a reaction. heterogeneous
endothermic
exothermic

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.

Any vitamins or supplements can be obtained without prescription and are widely used as alternative from western medications. most supplements are not valued by the fda or any other drug and food agencies.