Cobalt (III) chloride forms several octahedral complexes with ammonia. Which of the following will not give a test for chloride ions with silver nitrate at 25°C?

CoCl3·3NH3 will not give a test for chloride ions with silver nitrate at 25°C. This is because CoCl3·3NH3 is a coordination compound with the formula [Co(NH3)3Cl3]. In this complex, all three chloride ions are directly bonded to the cobalt(III) ion within the coordination sphere. Silver nitrate only reacts with free chloride ions (chloride ions outside the coordination sphere), not those coordinated to the metal ion. Therefore, since there are no free chloride ions present in [Co(NH3)3Cl3], it will not produce a precipitate with silver nitrate.