Which pair reacts to form a salt and hydrogen gas?
Answer and explanation
Correct answer: Acid and reactive metal
A sufficiently reactive metal can displace hydrogen from a dilute acid. The products are a salt and hydrogen gas; for example, Zn + 2HCl → ZnCl₂ + H₂. Therefore, option A is correct. Acid and base usually undergo neutralisation to form salt and water, while acid and metal carbonate form salt, water and carbon dioxide. Mixing water with common salt does not normally produce hydrogen gas.
Frequently asked questions
What is the correct answer to this question?
Acid and reactive metal
Why is this the correct answer?
A sufficiently reactive metal can displace hydrogen from a dilute acid. The products are a salt and hydrogen gas; for example, Zn + 2HCl → ZnCl₂ + H₂. Therefore, option A is correct. Acid and base usually undergo neutralisation to form salt and water, while acid and metal carbonate form salt, water and carbon dioxide. Mixing water with common salt does not normally produce hydrogen gas.
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.
