Question

A metal 'M' has shining appearance and reacts with hot water and also with dilute hydrochloric acid to evolve hydrogen gas. The metal 'M' is:

• A. can be copper because it lies above hydrogen in the reactivity series, i.e., more reactive than hydrogen
• B. can be gold because it lies below hydrogen in the reactivity series, i.e., more reactive than hydrogen
• C. cannot be gold because it lies above hydrogen in the reactivity series, i.e., less reactivity than hydrogen
• D. cannot be copper because it lies below hydrogen in the reactivity series, i.e., less reactive than hydrogen

Answer 1

The correct option is D cannot be copper because it lies below hydrogen in the reactivity series, i.e., less reactive than hydrogen

The reactivity series is a list of metals arranged in the order of their decreasing activities. The reactivity series follows the order:

$K>Na>Ca>Mg>Al>Zn>Fe>Pb>H>Cu>Hg>Ag>Au$

Thus, 'M' can't be copper as it lies below hydrogen in the reactivity series.