Answer
a) HCL, $H^{+}$ + $Cl^-$
b) 3.3
c) NaOH, $Na^+$ + $OH^-$
d) 9.8
Work Step by Step
a) Hydrochloric acid dissociates into hydrogen and chloride ions.
b) HCl is a strong acid and the dissociation is complete which means [HCl] = [H] =[Cl]
[HCL]=5.0$\times10^{-4}$ = [H]
pH= -log[H] =-log[5.0$\times10^{-4}$] = 3.3
c) Sodium hydroxide disassociates into sodium and hydroxide ions.
d) NaOH dissociates completely
[NaOH] = [Na] = [OH] =$7\times10^{-5}$
pH + pOH =14
pOH =14-pH
-log[OH] = 14-pH
pH = 14 + log[OH] =14 + log[$7\times10^{-5}$] = 9.8
