If 0.561 g of KOH is dissolved in water to give 200 mL of solution at 298 K. Calculate the concentrations of potassium, hydrogen and hydroxyl ions. What is its pH?
[KOHaq]=0.56115g/L=2.805g/l=2.805×156.11M=0.5MKOH(aq)→K+(aq)+OH−(aq)[OH−]=0.5M=[K+][H+][H−]=Kw[H+]Kw[OH−]=10−140.05=2×10−13M∴pH=12.70