Calculate the pressures, P, in atmospheres at which the mean free path, l, of a hydrogen molecule will be 5.00 μm, 5.00 mm, and 5.00 m at 20.0 °C. The diameter of a H2 molecule is 270 pm.

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.

Yeah, but what are you trying to ask?