When you see a equation how can u tell if it is exothermic or endothermic just by looking at it?

It’s b. mass i searched it up

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.

The answer is neonhope it

The answer to your q the total mass is 73