Problem: Calculate the ratio [NH3] / [NH4+] in ammonia/ammonium chloride buffered solutions with the following pH values:a. pH = 9.00

🤓 Based on our data, we think this question is relevant for Professor Vonderheide's class at UC.

FREE Expert Solution

We’re being asked to calculate the ratio [NH3]/[NH4+] in ammonia/ammonium chloride buffered solutions for ph 9.00.  


In an ammonia/ammonium chloride buffered solution, ammonia, NH3 is the weak base and the ammonium ion, NH4+ is its conjugate acid.


Recall that for buffers the pH can be determined using the Henderson-Hasselbalch equation:


pH=pKa+log weak baseconjugate acid


where:

[NH3] = concentration of the weak base, NH3

[NH4+] = concentration of conjugate acid, NH4


Since we're given the pH, we can solve for the ratio:  [NH3]/[NH4+]


But first, we need to determine Ka, Since ammonia is a weak base:


Kb = 1.76 x 10-5 (can be found in textbooks or online)


Recall that we can solve Kfrom Kb using the equation: 


Kw=Ka×KbKa=KwKb


**Kw = 1.0 x 10-14 at 25°C (value can be found in textbooks or online)

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Problem Details

Calculate the ratio [NH3] / [NH4+] in ammonia/ammonium chloride buffered solutions with the following pH values:

a. pH = 9.00

Frequently Asked Questions

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 Buffer concept. You can view video lessons to learn Buffer. Or if you need more Buffer practice, you can also practice Buffer practice problems.

What professor is this problem relevant for?

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

What textbook is this problem found in?

Our data indicates that this problem or a close variation was asked in Chemistry: An Atoms First Approach - Zumdahl 2nd Edition. You can also practice Chemistry: An Atoms First Approach - Zumdahl 2nd Edition practice problems.