Chemistry
Assertion (A): A crusty 'boiler scale' is formed in boilers when hard water is used.
Reason (R): Hard water contains bicarbonates of calcium and magnesium.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Water
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Answer
Both A and R are true and R is the correct explanation of A.
Explanation — Hard water contains bicarbonates of calcium and magnesium. When heated in boilers, these decompose into their respective carbonates, which are insoluble and get deposited as a hard, crusty layer on the inner walls of the boiler, known as boiler scale. Hence, both the assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
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