Which of the following reactions involve both a chemical and physical change? Question 3 options:

CO (g) + 2H2 (g) → CH3OH (l) (methanol formation)

CO (g) + H2O (g) → CO2 (g) + H2 (g) (the water gas shift reaction)

2C2H6O (g) + O2 (g) → 2C2H4O (g) + 2H2O (g) (the oxidation of ethanol to form acetaldehyde—the compound that causes you to feel a “hangover”.)

All of the above.

None of the above.

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.

Hcn is your answer my guy : )

#2- the hno3 has a h+ ion and the naoh has an oh- ion