Q37
4 marksSection E

The teacher while conducting practicals in the laboratory divided the students into three groups and gave them various solutions to find out their pH and classify them into acidic, basic and neutral solutions.

Group A - Lemon juice, vinegar, colourless aerated drink

Group B - Tomato juice, coffee, ginger juice

Group C - Sodium hydroxide, sodium chloride, lime water

(a) For the solutions provided, which group is/are likely to have pH value (i) less than 7, and (ii) greater than 7 ?

(b) List two ways of determining pH of a solution.

(c) Explain, why the sour substances such as lemon juice are effective in cleaning the tarnished copper vessels.

OR

(c) "pH has great importance in our daily life." Justify this statement by giving two examples.

Acids, Bases and Salts
pH of Various Solutions
Official Answer

(a) (i) Group A - Lemon juice, vinegar, colourless aerated drink; (ii) Group C - Sodium hydroxide, lime water

(b) Two ways of determining pH of a solution are: (1) using pH paper, and (2) using a pH meter.

(c) Sour substances such as lemon juice are effective in cleaning the tarnished copper vessels because they are acidic in nature and react with the oxide layer to form a salt and water, thereby removing the tarnish.

pHacidicbasicneutral

Analysis & Explanation

The pH of a solution can be determined using pH paper or a pH meter. Sour substances such as lemon juice are effective in cleaning the tarnished copper vessels because they are acidic in nature and react with the oxide layer to form a salt and water, thereby removing the tarnish.

Common Mistakes

  1. 1Group B has acidic solutions

Interesting Facts

The pH of a solution is a measure of its acidity or basicity.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2023?

This question carries 4 marks in the CBSE Class 10 Science 2023 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Acids, Bases and Salts" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "pH of Various Solutions" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2023 paper?

This question appears in Section E in the CBSE Class 10 Science 2023 paper.