Question

The formation constant of [Ni(NH3)6]2+ is 6 × 108 at 250C. If 50 ml of 2.0 M NH3 is added to 50 ml of 0.20 M solution of Ni2+, the concentration of Ni2+ ion will be nearly equal to

• A. 3 × 10-10 mole litre-1
• B. 2 × 10-10 mole litre-1
• C. 2 × 10-9 mole litre-1
• D. 4 × 10-8 mole litre-1

Answer 1

Answer: (D)

4 × 10-8 mole litre-1

Answer 2

Ni+2 + 6NH3 $\longrightarrow$ [Ni (NH3)]+6

Kf = 6 × 108

t =0 0.01 mole 0.1 mole 0

At equilibrium x (0.1 – 0.06) 0.1