For the reaction given below:
CoCl$$_3$$ · xNH$$_3$$ + AgNO$$_3$$(aq) $$\rightarrow$$
If two equivalents of AgCl precipitate out, then the value of x will be ______.

We need to find the value of x in CoCl₃·xNH₃ given that it produces 2 equivalents of AgCl with AgNO₃.

According to Werner’s coordination theory, only the ions in the ionization sphere (outside the coordination sphere) are free to react with AgNO₃ to precipitate as AgCl. Since 2 equivalents of AgCl precipitate out, there are 2 free Cl⁻ ions in the ionization sphere, which means 1 Cl⁻ is inside the coordination sphere.

The compound has Co³⁺ (since CoCl₃), which has a coordination number of 6. Total ligands in the coordination sphere = 6, and with 1 Cl⁻ inside, the number of NH₃ ligands = 6 − 1 = 5. $$[\text{CoCl}(\text{NH}_3)_5]\text{Cl}_2$$

In this formula, 2 Cl⁻ ions are outside the coordination sphere, precipitating with AgNO₃ as 2 AgCl, and the coordination number of Co is 5 (NH₃) + 1 (Cl) = 6. Therefore, x = 5.

The answer is 5.