The sequence of fractional precipitation Ddependent on the values of Kpand types of precipitates Same type of precipitate:the one with small K precipitates first when the concentration of ions needing to be precipitates is the same different types of preciptitate:calculation! 2 dependent on concentration of the ion to be precipitated The sequence of fractional precipitation ： ①dependent on the values of Ksp  and types of precipitates  Same type of precipitate: the one with small Ksp  precipitates first when the concentration of ions needing to be precipitates is the same ；  different types of preciptitate: calculation! ② dependent on concentration of the ion to be precipitated