Lanthanum hydrogen pyrophosphate, LaHP2O7.3H2O. - From a solution of a lanthanum salt sodium pyrophosphate throws down a white precipitate which then redissolves. On allowing the solution to stand, the acid pyrophosphate crystallises out in needles (Cleve).
The double salt LaNaP2O7 may be obtained in crystals by fusing together sodium metaphosphate and lanthana. |