A dilute acid gives gas with a metal, but the same acid generally gives no gas with copper. What is the main reason?
Answer and explanation
Correct answer: Copper is less reactive than hydrogen
The governing idea is the reactivity series. A metal placed above hydrogen can displace hydrogen from a dilute acid, producing hydrogen gas, for example Zn + 2HCl → ZnCl₂ + H₂. Copper lies below hydrogen, so it generally cannot displace hydrogen from dilute hydrochloric or dilute sulphuric acid. Thus option A is correct; the other statements are chemically unrelated or false.
Frequently asked questions
What is the correct answer to this question?
Copper is less reactive than hydrogen
Why is this the correct answer?
The governing idea is the reactivity series. A metal placed above hydrogen can displace hydrogen from a dilute acid, producing hydrogen gas, for example Zn + 2HCl → ZnCl₂ + H₂. Copper lies below hydrogen, so it generally cannot displace hydrogen from dilute hydrochloric or dilute sulphuric acid. Thus option A is correct; the other statements are chemically unrelated or false.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Metals and Non-metals. Topic: Reactivity series.
