7.50 mL of an acetic acid (CH3CO2H, 60.05 g/mole) stock solution was added to an analyte flask, along with 15 mL of water. 14.36 mL of 0.0915 M NaOH titrant was required to titrate the analyte solution to the endpoint. Calculate the concentration of the stock solution. Watch significant figures.

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

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.