Give reasons for the following: (i) Only one half of water molecule is shown in the formula of Plaster of Paris. (ii) Sodium hydrogen carbonate is used as an antacid. (iii) On strong heating, blue coloured copper sulphate crystals turn white.
Give reasons for the following: (i) Only one half of water molecule is shown in the formula of Plaster of Paris. (ii) Sodium hydrogen carbonate is used as an antacid. (iii) On strong heating, blue coloured copper sulphate crystals turn white.
Official answer
(i) The labelled diagram to show the preparation of hydrogen chloride gas in laboratory is: [Insert diagram] (ii) The gas evolved first with dry and then with wet litmus paper. In the case of wet litmus paper, the litmus paper shows change in colour. (iii) Dry HCl gas / HCl solution exhibits acidic character because it contains hydrogen ions (H+).
Hint
Recall the concepts of laboratory preparation of hydrogen chloride gas, testing of gases with litmus paper, and the acidic character of hydrogen ions.
Analysis and explanation
The question requires the student to provide a labelled diagram for the preparation of hydrogen chloride gas in laboratory, test the gas evolved with dry and wet litmus paper, and explain why dry HCl gas / HCl solution exhibits acidic character. The student needs to recall the concepts of laboratory preparation of hydrogen chloride gas, testing of gases with litmus paper, and the acidic character of hydrogen ions.
Question details
Q16 of 45 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2020
- Section
- Section B
- Marks
- 3
- Type
- Short Answer
- Chapter
- Acids, Bases and Salts
- Topic
- Acids, Bases and Salts
- Bloom's level
- Understanding
- Syllabus topic
- Acids, Bases and Salts
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2020?
This question carries 3 marks in the CBSE Class 10 Science 2020 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 "Acids, Bases and Salts" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2020 paper?
This is a Short Answer question from Section B in the CBSE Class 10 Science 2020 paper.