What will be the pH of a solution formed by mixing 40 mL of 0.10 M HCl with 10 mL of 0.45 M NaOH ?

40 mL of 0.1 M HCl=0.11000 × 40 = 0.004 moles of HClSimilarly, 10 mL of 0.45 M NaOH=0.451000 × 10 = 0.0045 moles of NaOHThus, NaOH left unneutralized = 0.0005 moles in a volume of 50 mL.Concentration of NaOH = 1000 × 0.000550 = 0.01= 10-2 MTherefore, OH-= 10-2 M  POH= 2  ;     PH=14-2 = 12