Question

Name two metals which will displace hydrogen from dilute acids, and two metals which will not.

Answer 1

Metals that can displace hydrogen from dilute acids are typically more reactive than hydrogen. Two examples of metals that will displace hydrogen from dilute acids are:

(1) Zinc (Zn): Zinc reacts with dilute acids, such as hydrochloric acid, to form zinc chloride and liberate hydrogen gas.$Zn+2HCl→ZnCl_2+H_2$

(2) Magnesium (Mg): Magnesium reacts with dilute acids, like hydrochloric acid, to produce magnesium chloride and release hydrogen gas.$Mg+2HCl→MgCl_2+H_2$

Metals that are less reactive than hydrogen will not displace hydrogen from dilute acids. Two examples of such metals are:

(1) Copper (Cu): Copper is less reactive than hydrogen and does not displace hydrogen from dilute acids under normal conditions.
$Cu+2HCl↛$ No reaction

(2) Silver (Ag): Silver is also less reactive than hydrogen and does not displace hydrogen from dilute acids.
$Ag+2HCl↛$ No reaction

These examples highlight the reactivity of metals with dilute acids and whether they can displace hydrogen from those acids.