Question

Write a net ionic equation and calculate K for the reaction in aq between acidic acid and sodium hydroxide. Given Ka (acidic acid) = 1.8 x 10^-5

Answer 1

Your question isn't clear. Do you mean acetic acid? Here is the equation.

CH3COOH + NaOH ==> CH3COONa + H2O.
The full ionic equation is
CH3COOH + Na^+ + OH^- ==>CH3COO^- + Na^+ + H2O
Drop the Na^+ from both sides to change to the net ionic equation.