Purchase Solution

Calculating PH Concentration

Not what you're looking for?

Ask Custom Question

The formation constant for zinc tetraammine ion [ Zn(NH3)4+2] is 4.1 x 108. What is the concentration of free Zn+2 in a solution of 3M NH3 (total ammonia) buffered to a pH of 9.0 if the total zinc concentration is 0.1M? The Kb for NH3 is 1.8 x 10-5

Purchase this Solution

Solution Summary

This Solution contains over 300 words and calculations to aid you in understanding the Solution to this question.

Solution Preview

For these types of multi-equilibrium questions, you need to use a few of assumptions....

First off, we see that we have total ammonia being equal to 3.0 M of total ammonia in a buffer of pH 9.0.

Using this, we set-up the buffer equation (Henderson-Hasselback somewhat) where it is:

Kb = [OH-] * [BH+]/[B]

Where Kb is the 1.8 x 10-5

[OH-] = 10^-pOH or in this case 10^-5

[BH+] is the concentration of NH4+ in our buffer system

[B] is the concentration of NH3 in our buffer system.

1.8 x 10^-5 = [10^-5] * [BH+]/[B]

Now we need algebra for the last ...

Purchase this Solution

Free BrainMass Quizzes
Match Elements with their Symbols

Elements are provided: choose the matching one- or two-letter symbol for each element.

General Chemistry - Classification of Matter

This test will assess your knowledge on the classification of matter which includes elements, compounds and mixtures.

Organic Chemistry Naming: Alkanes

This is a quiz which is designed to assist students with learning the nomenclature used to identify organic compounds. This quiz focuses on the organic compounds called Alkanes.


The quiz helps in revising basic concepts about thermochemistry.

Functional groups in Organic Chemistry

You will be tested on the names of functional groups in Organic Chemistry. It is very important to know the functional groups to understand Organic reactions.