Calculate the ph for a 0.3 m solution of (a) sodium leucinate

To get the pH value for a certain aqueous solution, the concentration of the hydronium ions (in moles per liter) should be know. This concentration is also known as the "molarity".
pH = -log [H3O+]

We are given that the molarity = 0.3 m
Therefore,
pH = -log[0.3] = 0.5228787

And a) oxygen i believe

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