(1)已知常温下,AgBr的K sp =4.9×10 -13 、AgI的K sp =8.3×10 -17 .现向含有AgI的饱和溶液中: ①加入固体AgNO 3 ,则c(I - )______(填“变大”、“变小”或“不变”,下同). ②若改加更多的AgI固体,则c(I - )______,而c(Ag + )______. ③若改加AgBr固体,则c(I - )______,而c(Ag + )______. (2)难溶弱电解质在水溶液中既存在溶解平又存在电离平.已知Cu(OH) 2 ?Cu 2+ +2OH - ,K SP =c(Cu 2+ )?[c(OH - )] 2 =2×l0 -20 .当溶液中各离子浓度方次的乘积大于溶度积时,则产生沉淀,反之固体溶解.某 CuSO 4 溶液里c(Cu 2+ )=0.02mol?L -1 ,如要生成Cu(OH) 2 沉淀,应调整沉淀pH使之大于______.