please help me answer this 2question with explanations. thank you veey much

5. You had 500000 much fun titrating this week that you performed a second weak acid - strong base titration and reached equivalence point (neutralization) by reacting 5mLL0.016mol/LNaOH(00) and 20mL of formic acid (HCHO2(a)) with a Ka(HCHO2(a) ) value =1.8104. Determine the pH at equilibrium. [8 marks] 4. A weak base, Aniline, reacts with water according to the reaction below. C6H5NH2(aq)+H2O(i)C6H5NH3+(aa)+OH(an) a) A sample of aniline is dissolved in water to produce 25.0mL of a 0.10M solution. The pH of the solution is 8.82. Calculate the equilibrium constant, Kb for this reaction. [3 marks] PH+POH=148.82+POH=14POH=148.82