🧪 What is pH Scale in Chemistry?
📌 What is the pH Scale?
The pH scale is a scale used to measure the acidity or basicity of a solution.
👉 In simple words: It tells us how acidic or basic a substance is.
🔗 Related Topics: Acids Bases and Salts, Difference Between Acids and Bases, Strong and Weak Acids
🧠 Key Points of pH Scale
- ✔ pH range is 0 to 14
- ✔ pH < 7 → Acidic
- ✔ pH = 7 → Neutral
- ✔ pH > 7 → Basic (Alkaline)
- ✔ Lower pH = Stronger acid
- ✔ Higher pH = Stronger base
⚖️ pH Scale Representation
🔍 Examples of pH Values
| Substance | pH Value | Nature |
|---|---|---|
| Battery acid | 0–1 | Strong acid |
| Lemon juice | 2 | Acidic |
| Vinegar | 3 | Acidic |
| Pure water | 7 | Neutral |
| Soap solution | 9–10 | Basic |
| Ammonia | 11 | Basic |
| Sodium hydroxide | 13–14 | Strong base |
⚙️ Importance of pH Scale
- 🔸 Helps identify acids and bases
- 🔸 Important in agriculture (soil pH)
- 🔸 Used in medicine (body pH balance)
- 🔸 Important in industries
📊 Real-Life Applications
- 🧪 Testing soil for farming
- 🪥 Toothpaste (basic to neutralize acids)
- 🧃 Food and beverages
- 🏊 Swimming pool maintenance
❗ Important Notes (Exam-Oriented)
- ⭐ pH scale ranges from 0 to 14
- ⭐ 7 is neutral (pure water)
- ⭐ Lower pH → more acidic
- ⭐ Higher pH → more basic
- ⭐ Each pH value represents change in strength
❓ FAQs on pH Scale
Q1. What is pH scale?
👉 Scale to measure acidity or basicity.
Q2. What is pH of neutral solution?
👉 7
Q3. What is pH less than 7?
👉 Acidic.
Q4. What is pH more than 7?
👉 Basic.
Q5. Which is stronger: pH 2 or pH 5?
👉 pH 2 is stronger acid.
📝 Practice Questions (With Answers)
Q1. Define pH scale.
👉 Answer: Scale used to measure acidity or basicity.
Q2. What is pH range?
👉 Answer: 0 to 14.
Q3. What is pH of pure water?
👉 Answer: 7.
Q4. Which is more acidic: pH 3 or pH 6?
👉 Answer: pH 3.
Q5. Which is more basic: pH 9 or pH 12?
👉 Answer: pH 12.
🧠 MCQ Questions (Test Yourself)
1. pH scale ranges from:
A) 1–10
B) 0–14
C) 0–7
D) 7–14
👉 Answer: B
2. Neutral solution has pH:
A) 0
B) 7
C) 14
D) 1
👉 Answer: B
3. pH less than 7 is:
A) Basic
B) Neutral
C) Acidic
D) Salt
👉 Answer: C
4. pH greater than 7 is:
A) Acidic
B) Neutral
C) Basic
D) Gas
👉 Answer: C
5. Which is more acidic?
A) pH 6
B) pH 5
C) pH 3
D) pH 7
👉 Answer: C
6. Which is more basic?
A) pH 8
B) pH 9
C) pH 12
D) pH 7
👉 Answer: C
7. pH of lemon is:
A) 7
B) 2
C) 10
D) 14
👉 Answer: B
8. pH of soap is:
A) Acidic
B) Neutral
C) Basic
D) Gas
👉 Answer: C
9. Lower pH means:
A) More basic
B) Less acidic
C) More acidic
D) Neutral
👉 Answer: C
10. Higher pH means:
A) More acidic
B) More basic
C) Neutral
D) No change
👉 Answer: B
Read & Learn More :
- Differences between Acids Bases And Salts
- Differences between strong acid and weak acid
- What is pH scale in chemistry
- Importance of pH in everyday life
- Differences between acid and alkali
- What is neutralization reaction
- Properties of acids and bases
- What are the indicators in chemistry
- differences between natural and synthetic indicators
- Uses of salts in daily life