Answer: Highest to lowest pH: Ba(OH)2, NaOH, N2H2, HOCL HCl
Step-by-step explanation:
Stronger the acid, lower the pH, stronger the base, higher the pH.
N2H2 weak base, Ba(OH)2 strong base, HOCL weak acid, NaOH strong base, HCl strong acid.
Ba(OH)2 has produces more H ions, so it has a higher pH than NaOH.