A chemist wants to calculate the amount of product that will be formed in a chemical reaction. Which of the following steps ensure that the chemist's calculations are in
alignment with the law of conservation of mass?

The answer is letter c

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.