# Problem: Copper(II) hydroxide, Cu(OH)2, has Ksp = 2.2 x 10 -20. For the reaction below, Keq = 4.0 x 10-7. What is Kf for Cu(NH3)42+?Cu(OH)2(s) + 4 NH3(aq) ⇋ Cu(NH3)42+(aq) + 2 OH -(aq)

###### FREE Expert Solution
89% (340 ratings)
###### FREE Expert Solution

We’re being asked to determine the formation constant of Cu(NH3)42+

We’re given the following reaction and equilibrium constant:

Cu(OH)2(s) + 4 NH3(aq)  Cu(NH3)42+(aq) + 2 OH(aq); Keq = 4.0 × 10–7

The Keq expression for this reaction is:

$\overline{){{\mathrm{K}}}_{{\mathrm{eq}}}{=}\frac{\mathrm{products}}{\mathrm{reactants}}{=}\frac{\left[\mathrm{Cu}\left({\mathrm{NH}}_{3}{{\right)}_{4}}^{2+}\right]\left[{\mathrm{OH}}^{-}{\right]}^{2}}{{\left[{\mathrm{NH}}_{3}\right]}^{4}}}$

Note that solids and liquids are not included in the equilibrium expression and that each concentration is raised by the stoichiometric coefficient: [NH3] is raised to 4, [Cu(NH3)42+] is raised to 1, and [OH] is raised to 2.

89% (340 ratings)
###### Problem Details

Copper(II) hydroxide, Cu(OH)2, has Ksp = 2.2 x 10 -20. For the reaction below, Keq = 4.0 x 10-7. What is Kf for Cu(NH3)42+?

Cu(OH)2(s) + 4 NH3(aq) ⇋ Cu(NH3)42+(aq) + 2 OH -(aq)

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Formation Constant concept. If you need more Formation Constant practice, you can also practice Formation Constant practice problems.

What is the difficulty of this problem?

Our tutors rated the difficulty ofCopper(II) hydroxide, Cu(OH)2, has Ksp = 2.2 x 10 -20. For t...as high difficulty.

How long does this problem take to solve?

Our expert Chemistry tutor, Dasha took 7 minutes and 33 seconds to solve this problem. You can follow their steps in the video explanation above.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor May's class at EKU.