The next three (3) problems deal with the titration of 301 ml of 0.501 m carbonic acid (h2co3) (ka1 = 4.3 x 10-7, ka2 = 5.6 x 10-11) with 1.5 m koh.
how many ml of the 1.5 m koh are needed to raise the ph of the carbonic acid solution to a ph of 6.635?

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na

That is a lot of moles that you have

Answerhund's rule;