If zinc is added to an acidic solution and a gas is evolved, what is the correct identification of that gas?
Answer and explanation
Correct answer: Hydrogen giving a pop sound with a burning splint
The governing concept is the reaction of an active metal with an acid. Zinc reacts with a dilute acid to form a salt and hydrogen: Zn + 2HCl → ZnCl₂ + H₂. Hydrogen is identified because it burns rapidly and produces a characteristic ‘pop’ when a burning splint is brought near it. Carbon dioxide would turn limewater milky, ammonia would affect red litmus, and oxygen would rekindle a glowing splint; therefore option A is correct.
Frequently asked questions
What is the correct answer to this question?
Hydrogen giving a pop sound with a burning splint
Why is this the correct answer?
The governing concept is the reaction of an active metal with an acid. Zinc reacts with a dilute acid to form a salt and hydrogen: Zn + 2HCl → ZnCl₂ + H₂. Hydrogen is identified because it burns rapidly and produces a characteristic ‘pop’ when a burning splint is brought near it. Carbon dioxide would turn limewater milky, ammonia would affect red litmus, and oxygen would rekindle a glowing splint; therefore option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
