Science
Assertion (A) : On adding dil. HCl to a test tube containing a substance ‘X’, a colourless gas is produced which gives a pop sound when a burning match stick is brought near it.
Reason (R) : In this reaction metal ‘X’ is displaced by Hydrogen.
options
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, and R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Acids Bases Salts
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Answer
A is true but R is false.
Reason —
Assertion (A) is true because when dilute hydrochloric acid (HCl) is added to a substance ‘X’, a colourless gas is evolved that produces a pop sound when a burning matchstick is brought near it. The gas is hydrogen (H2), which is released when a metal reacts with an acid and the pop sound confirms the presence of hydrogen gas.
Reason (R) is false because in this reaction the metal 'X' displaces hydrogen from the acid as metals are more reactive than hydrogen and the displaced hydrogen is released as a gas.
Hence, (A) is true, but (R) is false.
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