Copper(1) ions in aqueous solution react with NH3(aq) according to
Cu⁺(aq)+2NH₃(aq) → Cu(NH₃)₂⁺(aq)
Kf=6.3x10^{10}
Calculate the solubility (in g. L⁻¹) of CuBr(s) (Ksp = 6.3× 10⁻9) in 0.46 M NH₃(aq).