1. The Na+, K+, and NH4+ ions form soluble salts. Thus, NaCl, KNO3, (NH4)2SO4, Na2S, and (NH4)2CO3 are soluble. Na+、K+、NH4+盐溶2. The nitrate (NO3-) ion forms soluble salts. Thus, Cu(NO3)2 and Fe(NO...