text: what is an insoluble salt? i know it's a salt that is insoluble in water!!!!!!(duh) but what else can u tell me? some salts are insoluble in water. for example bas2 is insoluble. you can make it by adding two soluble salts solutions togeter. ie: bacl2 (aq.) + na2s (aq.) --> bas2 (ppt.) + na+(aq.) + cl- (aq.). the (aq.) means dissolved in water, (ppt.) means precipitate or solid formed. good luck!