Chemistry
Assertion (A): Pure hydrogen burns with a pop sound in air.
Reason (R): Hydrogen forms an explosive mixture with air.
- 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.
Answer
A is false but R is true.
Explanation — Pure hydrogen burns quietly (pale blue flame). The pop sound is heard only when hydrogen is mixed with air/oxygen. So, Assertion (A) is false.
Hydrogen forms an explosive mixture with air, which produces the pop on ignition. So, Reason (R) is true.
Related Questions
Assertion (A): On the earth, hydrogen is mostly found in the form of compounds.
Reason (R): Hydrogen is a highly reactive element.
- 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.
Assertion (A): In the laboratory preparation of hydrogen, granulated zinc is reacted with dilute acid.
Reason (R): Granulated zinc contains copper as an impurity.
- 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.
Assertion (A): Hydrogen is used for the extraction of less reactive metals like copper and lead.
Reason (R): Hydrogen is a good reducing agent.
- 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.
Assertion (A): Oxyhydrogen flame is used for cutting and welding metals.
Reason (R): For cutting and welding metals, a low temperature is required.
- 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.