For comparison purposes, all Mohr tirations should be carried out at about the same temperature, since the solubilities of Silver Chloride and Silver Chromate depend on temperature. Good stirring during the addition of the Silver Nitrate is also required; otherwise, Silver Chromate that forms locally before the endpoint can become occluded in the Silver Chloride precipitate instead of redissolving. Poor agitation could lead to an endpoint that is neither sharp nor reproducible. The reactions for the Mohr titration are:
Ag+ + Cl- → AgCl (white precipitate)
2 Ag+ (excess) + CrO42- → Ag2CrO4 (red precipitate at endpoint)