Question

Fill the table 2.2 pg-26 of chapter 2 of class 10.

Answer 1

Hey there!

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⇒ Objective

To determine the pH values of the given solutions with the help of pH paper.

⇒ Materials Required

Saliva, lemon juice, tomato juice, carrot juice, soda water, coffee, tea water, 1 M NaoH solution, 1 M HCl solution and pH paper.

⇒ Procedure

1. Take different solutions in different test tubes,
2. Now, place one or two drops of lemon juice on a pH paper strip.
3. Note the colour obtained.
4. Repeat the same procedure with each given solution using a new pH paper strip and note the colours obtained.

⇒ Observation

1. Saliva (before meal) :- Green ; pH = 7.4 ; (Weakly alkaline) Basic.
2. Saliva (after meal) :- Depends upon the food eaten.
3. Lemon juice :- Pink ; pH = 2.5 ; Acidic.
4. Colourless aerated drink :- Yellow/Green ; pH = 5.0 - 6.0 ; Acidic
5. Carrot juice :- Yellow/Green ; pH = 5.0 - 6.0 ; Acidic.
6. Coffee :- Yellow ; pH = 5.0 ; Acidic.
7. Tomato juice :- Orange ; pH = 4.1 ; Acidic.
8. Tap water :- Green ; pH = 6.5 - 8.5 (7.0) ; Neutral
9. 1 M NaOH :- Purple ; pH = 14.0 ; Strongly Alkaline (Basic)
10. 1 M HCl :- pH = 0.0 ; Acidic.

⇒ Conclusion

Solutions having pH value less than 7 are acidic while those having pH value greater than 7 are basic in nature. As pH value of water is 7, therefore it is considered neither acidic nor basic but neutral.

Hope it helps!

Answer 2

Explanation:

the physical of a neutral solutions is 7 .values less than 7 on the pH scale represent the acidic solutions,while the pH values increases from 7to 14 represent an alkaline ( basic )...