Question

The step wise formation of [Cu(NH₃)₄]²⁺ is given below.

The value of stability constants K₁ , K₂ , K₃ and K₄ are 10⁴, 1.58 × 10³, 5 × 10² and 10² respectively. The overall equilibrium constants for dissociation of [Cu(NH₃)₄]²⁺ is x × 10^–12.  The value of x is ...... (Rounded off to the nearest integer)

Answer 1

So

K = K₁ × K₂ × K₃ × K₄

= 10⁴ × 1.58 × 10³ × 5 × 10² × 10²

K = 7.9 × 10¹¹

Where K → Equilibrium constant for formation of [Cu(NH₃)₄]²⁺

So equilibrium constant (K') for dissociation of [Cu(NH₃)₄]²⁺ is \(\frac{1}{K}\)

K' = \(\frac{1}{K}\) 

K' = \(\frac{1}{7.9\times10^{11}}\)

= 1.26 × 10^–12 = (x × 10^–12)

So the value of x = 1.26