The existing chemical fertilizers A, B, C, and D that have lost their labels may be potassium chloride, ammonia, ammonium sulfate, or phosphate rock powder. In order to identify them, the following experiments were conducted:

(1) Ammonia is liquid, phosphate rock powder is gray-white solid, potassium chloride and ammonium sulfate are white solids, so A is ammonia water, B is phosphate rock powder; C and D are potassium chloride, One of ammonium sulfate;

(2) Add water to dissolve, potassium chloride and ammonium sulfate are easily soluble in water, phosphate rock powder is insoluble in water;

(3) Add hydrated lime After grinding, the pungent smell produced is ammonium sulfate, so D is ammonium sulfate and C is potassium chloride.

So the answer is: ammonia water; phosphate rock powder; potassium chloride; ammonium sulfate.