Both guys are in aqueous state. The same way we wrote equilibrium expressions for acid and for water, we can also write equilibrium expressions for bases as well. Except now we replace our ka and Kw with KB or Dionization constant for our base. So KB is equal to the conjugate acid or the concentration of the conjugate acid times the concentration of our hydroxide divided by our conjugate base. So, in terms of this reaction, it's this guy. The concentration of this guy times the concentration of this guy.