Acids, Bases and Salts | Class 10 | Activity 2.11 with Solution

Activity 2.11

• Test the pH values of solutions given in Table 2.2.
• Record your observations.
• What is the nature of each substance on the basis of your observations?

Solution	Colour of pH paper	Approximate pH value	Nature of substance
1.    Saliva (before meal)
2.    Saliva (after meal)
3.    Lemon juice
4.    Colourless aerated drink
5.    Carrot juice
6.    Coffee
7.    Tomato juice
8.    Tap water
9.    1M NaOH
10. 1M HCl

✅ Answer:

Solution	Colour of pH paper	Approximate pH value	Nature of substance
1.    Saliva (before meal)	Green	6.8 – 7.4	Slightly acidic to basic
2.    Saliva (after meal)	Yellow green	5.8	Acidic
3.    Lemon juice	Orange	2.2	Acidic
4.    Colourless aerated drink	Yellow	4.0	Acidic
5.    Carrot juice	Yellow green	6.0	Acidic
6.    Coffee	Yellow	4.5	Acidic
7.    Tomato juice	Yellow	4.3	Acidic
8.    Tap water	Green	6 – 8.5	Varied
9.    1M NaOH	Dark blue	14	Basic
10. 1M HCl	Red	0	Acidic

• Activity 2.1
• Activity 2.2
• Activity 2.3
• Activity 2.4
• Activity 2.5
• Activity 2.6
• Activity 2.7
• Activity 2.8
• Activity 2.9
• Activity 2.10
• Activity 2.11
• Activity 2.12
• Activity 2.13
• Activity 2.14
• Activity 2.15

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