查水的Kf=1.86K/kg.mol凝固点下降=Kf*质量摩尔浓度0.56=1.86K/kg.mol-1 * MB得MB=0.3011 mol•kg-1则n=0.3011*50/1000=0.0151 molM=0.90/ 0.0151=59.60 g/mol
