In a qualitative analysis, \(Bi^{3+}\) is detected by appearance of precipitate of \(BiO(OH)\). Calculate pH when the following equilibrium exists at \(298K\):
\[
BiO(OH)(s)\rightleftharpoons BiO^+(aq)+OH^-(aq)
\]
\[
K=4\times10^{-10}
\]
\[
\text{Given: }\log2=0.3010
\]