Q21
2 marksVery Short AnswerSection B

A crystalline substance of green colour 'X' emits gases of characteristic odour when heated over a flame. It first loses water and changes colour. On further heating, it decomposes and produces a solid compound Y.

(a) Identify 'X' and 'Y'.

(b) State the change in colour observed when 'X' is heated.

Acids, Bases and Salts
Acids, Bases and Salts
Official Answer

(a) 'X' is copper sulphate and 'Y' is anhydrous copper sulphate.

(b) The colour changes from blue to white.

Analysis & Explanation

The question describes a crystalline substance 'X' that emits gases of characteristic odour when heated over a flame. It first loses water and changes colour. On further heating, it decomposes and produces a solid compound Y. Based on the description, 'X' is copper sulphate and 'Y' is anhydrous copper sulphate. The colour changes from blue to white.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2025?

This question carries 2 marks in the CBSE Class 10 Science 2025 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 2025 paper?

This is a Very Short Answer question from Section B in the CBSE Class 10 Science 2025 paper.