Magnesium gives brisk bubbles with an acid, but copper does not. What is the reason?
Answer and explanation
Correct answer: Magnesium is more reactive than copper
The governing concept is the reactivity series of metals. Metals above hydrogen can generally displace hydrogen from dilute acids. Magnesium is above hydrogen and reacts to form a magnesium salt and hydrogen gas, producing brisk bubbles: Mg + 2HCl → MgCl₂ + H₂. Copper is below hydrogen, so it does not normally liberate hydrogen from dilute non-oxidising acids. Therefore option A is correct; the other statements are chemically false.
Frequently asked questions
What is the correct answer to this question?
Magnesium is more reactive than copper
Why is this the correct answer?
The governing concept is the reactivity series of metals. Metals above hydrogen can generally displace hydrogen from dilute acids. Magnesium is above hydrogen and reacts to form a magnesium salt and hydrogen gas, producing brisk bubbles: Mg + 2HCl → MgCl₂ + H₂. Copper is below hydrogen, so it does not normally liberate hydrogen from dilute non-oxidising acids. Therefore option A is correct; the other statements are chemically false.
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.
