Calculate pH of solution whose 100 ml contains 0.2 g NaOH dissolved in it.

100 ml solution of NaOH solution= 0.2 g NaOH∴  1000 ml solution of NaOH contains = 2 g NaOHNormality of solution = 240 = 0.05 N=[OH-]∴    H+ = 10-140.05=15×10-12=2×10-13PH=-log(2×10-13)     =13-log 2      =12.699