Determine the pH of a 0.21 M solution of pyridinium nitrate (C5H5NHNO3) at 25°C. [Pyridinium nitrate dissociates in water to give pyridinium ions (C5H5NH*), the conjugate acid of pyridine (K = 1.7 × 10-9), and nitrate ions (NO3).] pH =
Ionic Equilibrium
Chemical equilibrium and ionic equilibrium are two major concepts in chemistry. Ionic equilibrium deals with the equilibrium involved in an ionization process while chemical equilibrium deals with the equilibrium during a chemical change. Ionic equilibrium is established between the ions and unionized species in a system. Understanding the concept of ionic equilibrium is very important to answer the questions related to certain chemical reactions in chemistry.
Arrhenius Acid
Arrhenius acid act as a good electrolyte as it dissociates to its respective ions in the aqueous solutions. Keeping it similar to the general acid properties, Arrhenius acid also neutralizes bases and turns litmus paper into red.
Bronsted Lowry Base In Inorganic Chemistry
Bronsted-Lowry base in inorganic chemistry is any chemical substance that can accept a proton from the other chemical substance it is reacting with.
![**Problem: Determining the pH of Pyridinium Nitrate Solution**
**Objective:**
Calculate the pH of a 0.21 M solution of pyridinium nitrate (C₅H₅NHNO₃) at 25°C.
**Background Information:**
- Pyridinium nitrate dissociates in water to form pyridinium ions (C₅H₅NH⁺) and nitrate ions (NO₃⁻).
- The pyridinium ion is the conjugate acid of pyridine.
- The base dissociation constant, \(K_b\), for pyridine is \(1.7 \times 10^{-9}\).
**Task:**
Calculate the pH of the solution using the given data.
**Calculation:**
\[ \text{pH} = \_\_\_\_ \]
---
**Notes for Students:**
- Use the given \(K_b\) value to find \(K_a\) for the pyridinium ion, noting that \(K_w = 1.0 \times 10^{-14}\).
- Apply the formula \(K_a = \frac{K_w}{K_b}\).
- Set up the equilibrium expression for the dissociation of pyridinium ions and solve for \(H^+\) concentration.
- Lastly, use \(\text{pH} = -\log[H^+]\) to find the pH.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F2ceb2d65-29b4-49d4-9830-4ba06589987b%2F27675e7b-d631-48b6-b402-495cd84ab75c%2Fcqb2lpt_processed.jpeg&w=3840&q=75)

To calculate pH , we need to calculate the concentration of hydronium ion given by pyridinium ion on dissociation in water.
So first we need to calculate Ka of pyridinium ion , then using its Ka and concentration we can calculate [H3O+] . From this we can calculate pH.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 1 images









