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This section contains Assertion (A) P...

This section contains
Assertion (A) Pure water obtained from different sources always contains hydrogen and oxygen in the ratio 1:8 by mass.
Reason ( R) A chemical compound always contains elements combined together in same proportion by mass.

A

Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion

B

Both Assertion and reason are correct but Reason is not the correct explanation of Assertion

C

Assertion is correct but Reason is incorrect.

D

Both Assertion and Reason are incorrect

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the given assertion and reason, we will break down the statements step by step. ### Step 1: Understanding the Assertion (A) The assertion states that "Pure water obtained from different sources always contains hydrogen and oxygen in the ratio 1:8 by mass." - **Explanation**: Water (H₂O) is a chemical compound made up of two hydrogen atoms and one oxygen atom. The atomic mass of hydrogen is approximately 1 g/mol, and that of oxygen is approximately 16 g/mol. Therefore, the mass ratio of hydrogen to oxygen in water is calculated as follows: - Mass of hydrogen in water = 2 atoms × 1 g/mol = 2 g - Mass of oxygen in water = 1 atom × 16 g/mol = 16 g - The mass ratio of hydrogen to oxygen = 2 g : 16 g = 1 : 8. ### Step 2: Understanding the Reason (R) The reason states that "A chemical compound always contains elements combined together in the same proportion by mass." - **Explanation**: This statement is a fundamental principle of chemistry known as the law of definite proportions. It states that a chemical compound is composed of the same elements in the same proportion by mass, regardless of the source or how it was prepared. ### Step 3: Evaluating the Truth of the Statements - The assertion (A) is **true** because pure water does indeed have a mass ratio of hydrogen to oxygen of 1:8. - The reason (R) is also **true** as it accurately describes a property of chemical compounds. ### Step 4: Conclusion Since both the assertion and the reason are true, and the reason correctly explains the assertion, we conclude that the correct answer is that both statements are true, and the reason is a correct explanation of the assertion. ### Final Answer Both the assertion and reason are true, and the reason correctly explains the assertion. ---
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