• A solution is made with 1.1×10-3 M Zn(NO3)2(aq) and
0.150 M NH3(aq)
After the solution reaches equilibrium, what concentration of
“naked” Zn2+(aq) cation remains?
The complex Zn(NH3)42+ has Kf = 2.8×109.
answer the reaction should be like this
Zn 2+ + 4 NH3 <------------> ZN (NH3)42+
as we are given with the ampunt of ZN(NO3)2 = 0.0011 so
0.0011 + 4(0.0011) ------> 0.0011
extra NH3 = .150 -.0044 = 0.1456 M
Kf= [ ZN (NH3)42+ ] / [Zn 2+ ] [ NH3]4
2.8 * 109 = 0.0011/ [Zn 2+ ] [ 0.1456 M ]4
[Zn2+ ] = 0.0011 / 2.8 * 109 * 4.49 * 10-4
= 0.0011 / 12.57 *105 = 8.75 * 10-10 M
Get Answers For Free
Most questions answered within 1 hours.