Ikind of get how to do this but don’t fully #’s 2, 3, and 4

2. 109 g NaCl

3. 31.9 g ZnCl2

4. 15.4 g Al2O3

Explanation: First find moles of the given compound

Next do the mole ratio between both compounds

Convert moles to mass.

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 correct answer is weight.