Aqueous Strong Acid or Base

To find the pH of .2M HCl_aq, first realize that HCl is a strong acid. That means it completely dissociates into H⁺ and Cl^-. The concentration of H⁺ is there .2M. Thus, the pH is: - log (.2) = .7

Ti find the pH of .2M NaOH_aq, first realize that NaOH is a strong base. That means it completely dissociates into OH^- and Na⁺. The concentration of OH^- is .2M. Therefore, the pOH is: - log (.2) = .7 & the pH will be: 14-.7 = 13.3