Identify Each Of These Substances As Acidic, Basic, Or Neutral.- Rainwater, P H = 8.5 PH = 8.5 P H = 8.5 - Cola, P O H = 11 POH = 11 PO H = 11 - Tomato Juice, P O H = 10 POH = 10 PO H = 10 - Liquid Drain Cleaner, P O H = 0 POH = 0 PO H = 0
Understanding pH and pOH: A Guide to Identifying Acidic, Basic, and Neutral Substances
Introduction
In chemistry, the pH and pOH scales are used to measure the acidity or basicity of a solution. pH is a measure of the concentration of hydrogen ions (H+) in a solution, while pOH is a measure of the concentration of hydroxide ions (OH-). In this article, we will explore how to identify each of the given substances as acidic, basic, or neutral based on their pH and pOH values.
pH and pOH: What's the Difference?
Before we dive into the examples, let's quickly review the difference between pH and pOH. pH is defined as the negative logarithm of the concentration of hydrogen ions in a solution:
pH = -log[H+]
pOH, on the other hand, is defined as the negative logarithm of the concentration of hydroxide ions in a solution:
pOH = -log[OH-]
At 25°C, the relationship between pH and pOH is given by the equation:
pH + pOH = 14
This equation shows that pH and pOH are inversely related, meaning that if one increases, the other decreases.
Example 1: Rainwater with a pH of 8.5
Rainwater has a pH of 8.5, which is slightly basic. To determine whether it is acidic, basic, or neutral, we can use the pH scale:
- pH < 7: Acidic
- pH = 7: Neutral
- pH > 7: Basic
Since the pH of rainwater is greater than 7, it is basic. However, the pH is not very high, so it is not strongly basic.
Example 2: Cola with a pOH of 11
Cola has a pOH of 11, which is slightly acidic. To determine whether it is acidic, basic, or neutral, we can use the pOH scale:
- pOH < 7: Basic
- pOH = 7: Neutral
- pOH > 7: Acidic
Since the pOH of cola is greater than 7, it is acidic. However, the pOH is not very high, so it is not strongly acidic.
Example 3: Tomato Juice with a pOH of 10
Tomato juice has a pOH of 10, which is slightly acidic. To determine whether it is acidic, basic, or neutral, we can use the pOH scale:
- pOH < 7: Basic
- pOH = 7: Neutral
- pOH > 7: Acidic
Since the pOH of tomato juice is greater than 7, it is acidic. However, the pOH is not very high, so it is not strongly acidic.
Example 4: Liquid Drain Cleaner with a pOH of 0
Liquid drain cleaner has a pOH of 0, which is extremely basic. To determine whether it is acidic, basic, or neutral, we can use the pOH scale:
- pOH < 7: Basic
- pOH = 7: Neutral
- pOH > 7: Acidic
Since the pOH of liquid drain cleaner is less than 7, it is basic. In fact, it is extremely basic, which means it is a strong base.
Conclusion
In conclusion, we have identified each of the given substances as acidic, basic, or neutral based on their pH and pOH values. Rainwater is slightly basic, cola is slightly acidic, tomato juice is slightly acidic, and liquid drain cleaner is extremely basic. Understanding pH and pOH is crucial in chemistry, as it helps us determine the acidity or basicity of a solution and predict its behavior in various chemical reactions.
pH and pOH: A Summary
| Substance | pH | pOH | Classification |
|---|---|---|---|
| Rainwater | 8.5 | 5.5 | Basic |
| Cola | 11 | Acidic | |
| Tomato Juice | 10 | Acidic | |
| Liquid Drain Cleaner | 0 | Basic |
Frequently Asked Questions
- Q: What is the difference between pH and pOH? A: pH is a measure of the concentration of hydrogen ions in a solution, while pOH is a measure of the concentration of hydroxide ions in a solution.
- Q: How do I determine whether a substance is acidic, basic, or neutral? A: Use the pH or pOH scale to determine whether the value is less than 7 (acidic), equal to 7 (neutral), or greater than 7 (basic).
- Q: What is the relationship between pH and pOH? A: pH + pOH = 14, which means that pH and pOH are inversely related.
References
- "pH and pOH" by Chemistry LibreTexts
- "Acid-Base Chemistry" by Purdue University
- "pH and pOH" by Khan Academy
Frequently Asked Questions: pH and pOH
Introduction
In our previous article, we explored the concept of pH and pOH and how to identify acidic, basic, and neutral substances based on their pH and pOH values. In this article, we will answer some of the most frequently asked questions about pH and pOH.
Q: What is the pH scale?
A: The pH scale is a measure of the concentration of hydrogen ions in a solution, ranging from 0 to 14. A pH of 7 is neutral, while a pH less than 7 is acidic and a pH greater than 7 is basic.
Q: What is the pOH scale?
A: The pOH scale is a measure of the concentration of hydroxide ions in a solution, ranging from 0 to 14. A pOH of 7 is neutral, while a pOH less than 7 is basic and a pOH greater than 7 is acidic.
Q: What is the relationship between pH and pOH?
A: The relationship between pH and pOH is given by the equation: pH + pOH = 14. This means that pH and pOH are inversely related, meaning that if one increases, the other decreases.
Q: How do I determine whether a substance is acidic, basic, or neutral?
A: Use the pH or pOH scale to determine whether the value is less than 7 (acidic), equal to 7 (neutral), or greater than 7 (basic).
Q: What is the pH of pure water?
A: The pH of pure water is 7, which is neutral.
Q: What is the pOH of pure water?
A: The pOH of pure water is 7, which is neutral.
Q: How do I calculate the pH of a solution?
A: To calculate the pH of a solution, you need to know the concentration of hydrogen ions in the solution. You can use the formula: pH = -log[H+], where [H+] is the concentration of hydrogen ions in moles per liter.
Q: How do I calculate the pOH of a solution?
A: To calculate the pOH of a solution, you need to know the concentration of hydroxide ions in the solution. You can use the formula: pOH = -log[OH-], where [OH-] is the concentration of hydroxide ions in moles per liter.
Q: What is the pH of a strong acid?
A: The pH of a strong acid is less than 7, typically around 1-2.
Q: What is the pH of a strong base?
A: The pH of a strong base is greater than 7, typically around 12-14.
Q: What is the pOH of a strong acid?
A: The pOH of a strong acid is greater than 7, typically around 12-14.
Q: What is the pOH of a strong base?
A: The pOH of a strong base is less than 7, typically around 1-2.
Q: Can pH and pOH be negative?
A: No, pH and pOH cannot be negative. The pH and pOH scales are logarithmic, so the values are always positive.
Q: Can pH and pOH be greater than 14?
A: No, pH and pOH cannot be greater than 14. The pH and pOH scales are logarithmic, so the values are always less than or equal to 14.
Conclusion
In conclusion, we have answered some of the most frequently asked questions about pH and pOH. We hope this article has provided you with a better understanding of these important concepts in chemistry.
pH and pOH: A Summary
| Substance | pH | pOH | Classification |
|---|---|---|---|
| Pure Water | 7 | 7 | Neutral |
| Strong Acid | < 7 | > 7 | Acidic |
| Strong Base | > 7 | < 7 | Basic |
| Weak Acid | < 7 | > 7 | Acidic |
| Weak Base | > 7 | < 7 | Basic |
References
- "pH and pOH" by Chemistry LibreTexts
- "Acid-Base Chemistry" by Purdue University
- "pH and pOH" by Khan Academy