Chemistry Help?

Question

Consider the following four titrations:

i. 150 mL of 0.2 M NH3 (Kb=1.8*10^(-5) by 0.2 M HCl

ii.150 mL of 0.2 M NH3 ) by 0.2 M NaOH

III.150 mL of 0.2 M HOCl(Ka=3.5*10^(-8) by 0.2 M NaOH

iv.150 mL of 0.2 M HF(Ka=7.2*10^(-4) by 0.2 M NaOH

a. Rank the four titrations in order of increasing pH at the halfway point to equivalence.

b. Rank the four titrations in order of increasing pH at the equivalence point

c. Which titration requires the largest volume of titrant (HCL OR NAOH) to reach the equivalence point?