pH Value Explained: Acidity, Basicity, and Neutrality
The pH scale is a fundamental concept in chemistry used to measure how acidic or basic (alkaline) a water-based solution is. This scale typically ranges from 0 to 14.
Understanding Acidity: pH Less Than 7
A solution is considered acidic when its pH value is below 7. This indicates that the concentration of hydrogen ions (\(H^+\)) in the solution is greater than the concentration of hydroxide ions (\(OH^-\)). The lower the pH value, the stronger the acidity of the solution.
Neutral and Basic Solutions Defined
On the other hand, a solution is defined as neutral if its pH value is exactly 7. In a neutral solution, the concentration of hydrogen ions (\(H^+\)) is equal to the concentration of hydroxide ions (\(OH^-\)). Pure water is an example of a neutral solution.
A solution is classified as basic or alkaline when its pH value is greater than 7. In basic solutions, the concentration of hydroxide ions (\(OH^-\)) exceeds the concentration of hydrogen ions (\(H^+\)).
pH Scale Summary
The relationship between pH value and the nature of the solution can be summarized as follows:
| pH Range | Solution Type |
|---|---|
| pH < 7 | Acidic |
| pH = 7 | Neutral |
| pH > 7 | Basic (Alkaline) |
Identifying Acidic Solutions
Given that the question asks to identify the type of solution when the pH value is less than 7, we refer to the definition above. A pH value strictly less than 7 signifies an acidic condition. Common examples of acidic substances include vinegar, lemon juice, and stomach acid.
Analyzing Other Options
Let's look at why the other options provided are not the correct classification for a solution with a pH less than 7:
- Neutral solution: This type of solution has a pH value exactly equal to 7.
- Basic solution: This type of solution has a pH value greater than 7.
- Hypotonic solution: This term is related to osmosis and describes a solution that has a lower solute concentration, and thus a higher water concentration, compared to another solution. It does not directly relate to the acidity or basicity (pH) of the solution itself.
Therefore, a solution with a pH value less than 7 is definitively an acidic solution.
Similar Questions
- Consider the following statements regarding bases and alkalis :
1. All bases dissolve in water.
2. Bases which are soluble in water are called alkalis.
3. An alkali is soapy to touch, bitter and corrosive.
4. Addition of water to an alkali generates heat.
Which of the statements given above are correct ? Number of electrons present in the species H2, He, H2 and O2 respectively are:
Important Questions from Acids, Bases & Salts
When a large amount of carbon dioxide dissolves in a water body, the water becomes acidic because of the formation of which of the following acids?
Which one of the following oxides is a neutral oxide?
- Which of the following solutions is slightly acidic due to hydrolysis?
- Which of the following foods would you advise to neutralise excess stomach acids?
- What is the primary contributor to the sour taste in foods like lemons, vinegar and yoghurt?
