Question

When copper (Cu) reacts with hydrochloric acid (HCl). What will happen?
(A) React vigorously
(B) No reaction
(C) React modestly
(D) React slowly

Answer 1

Hint: As we know, copper is one of the “noble metals.” Just like the noble gases are gases that do not readily react, the noble metals do not readily in a lot of cases. So, try to figure out what will happen when copper reacts with hydrochloric acid.

Complete step by step answer.
> Let us discuss metals and reactions with dilute acids briefly.
As we know all metals do not react with the same rate.
K>Na>Ca>Mg>Al>Zn>Fe>Pb>H>Cu>Hg>Ag>Au
- Potassium, Sodium and calcium are the metals with the highest reactivates. They react with dilute acids at the room temperature itself.
- The metals of moderate reactivity are magnesium, aluminum, zinc, iron and copper.
- Mercury, silver, gold are the metals with low reactivity.
- In the series the metals above hydrogen react with dilute acids to give salt and hydrogen gas.
- The metals below hydrogen do not react with dilute acids. Because they are less reactive than hydrogen and they cannot displace hydrogen from dilute acid.
- I guess you already got your answer. Yes, it is obvious that copper will not react with hydrochloric acid for the simple reason it’s below hydrogen in the reactivity series. So, copper cannot replace the hydrogen in HCl to form $Cu{Cl}_2$ .
$Cu(s)+HCl(aq)⟶noreaction$
Hence, when copper (Cu) reacts with hydrochloric acid (HCl) there will be no reaction. Therefore, option B is the required answer.

Note: You should know that the most reactive element is fluorine, the first element in the halogen group and the most reactive metal is francium, which is the last alkali metal and the least reactive elements are the noble gases.