If copper metal does not give hydrogen gas with dilute acid, what is the most correct reason?
Answer and explanation
Correct answer: Copper is less reactive than hydrogen
A metal liberates hydrogen from a dilute non-oxidising acid only when it is above hydrogen in the reactivity series. Copper lies below hydrogen, so it cannot normally displace H⁺ ions from dilute hydrochloric or dilute sulphuric acid. Consequently, hydrogen gas is not evolved under these conditions. The result is explained by relative reactivity, not by copper being a gas, converting acid to base, or dissolving instantly in water.
Frequently asked questions
What is the correct answer to this question?
Copper is less reactive than hydrogen
Why is this the correct answer?
A metal liberates hydrogen from a dilute non-oxidising acid only when it is above hydrogen in the reactivity series. Copper lies below hydrogen, so it cannot normally displace H⁺ ions from dilute hydrochloric or dilute sulphuric acid. Consequently, hydrogen gas is not evolved under these conditions. The result is explained by relative reactivity, not by copper being a gas, converting acid to base, or dissolving instantly in water.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Metals and Non-metals. Topic: Reactivity series.
