From the value kf=1.2×109 for ni(nh3)62+, calculate the concentration of nh3 required to just dissolve 0.011 mol of nic2o4 (ksp = 4×10−10) in 1.00 l of solution. (hint: you can neglect the hydrolysis of c2o42− because the solution will be quite basic.)

The molar concentration of NH₃ required is 0,54M

Explanation:

In this problem you need to sum the two reactions, thus:

NiC₂O₄(s) ⇄ Ni²⁺ + C₂O₄²⁻ ksp: 4x10⁻¹⁰

Ni²⁺ + 6NH₃ ⇄ Ni(NH₃)₆²⁺ kf: 1,2x10⁹

The sum of the reactions is:

NiC₂O₄(s) + 6NH₃ ⇄ Ni(NH₃)₆²⁺ + C₂O₄²⁻ k' = kf×ksp = 0,48

The equation for this equilibrium is:

If we are lloking for the complete dissolution of 0,11mol/L of NiC₂O₄(s), the molar concentrations of Ni(NH₃)₆²⁺ and C₂O₄²⁻ are 0,11M, replacing:

The molar concentration of NH₃ required is:

[NH₃]⁶ = 0,0252

[NH₃] = ⁶√0,0252

[NH₃] = 0,54M

I hope it helps!

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.