Write expression for ka for the reaction of carbonic acid

Question

1. If you wish a buffer to have a pH of 10.00, what is the desired [H₃O⁺]?

2. In the buffer from 6, you want to select a weak acid (one of the conjugate pair) with a Ka close to that value of [H₃O⁺]. Explain why, using the expression for Ka.

Every Ka is for a reaction HA (aq) + H₂O (l) ↔ H₃O⁺ (aq) + A^? (aq).

a) Write the chemical equilibrium for the acid H2CO3 for which the equilibrium constant is the Ka of carbonic acid.

b) Write the expression for the Ka for the reaction of carbonic acid with water.

c) If the patient's pH is 7.30, calculate [H₃O⁺]

How many mL of a 0.175M solution of NaOH (aq) will react with 150.0 mL of a 0.158 M H₃PO₄ (aq) solution?