Question

What happens when acid reacts with a metal? Give the chemical equation of the reaction involved.

Answer 1

Acid is defined as the hydrogen containing substance which has the tendency to donate a proton or the hydrogen ion to the other substance. Substances which are acidic in nature are generally sour in taste. They have the tendency to turn the litmus paper from blue to red. Whereas metal are the minerals and inorganic in nature with a shiny appearance.

Complete answer:
When an acid is treated or reacted with a metal we see the formation of salt takes place and the hydrogen gas is evolved. The metals which have the ability to be active more than that of acids undergo the single displacement reactions. While we observe the reactivity of metals with hydrogen, we see that the metal potassium is the most reactive metal with hydrogen and the metal platinum is the least reactive metal with hydrogen. When the metals which are reactive in nature tend to react with dilute acids the reaction which is violent in nature takes place but during the reaction of least reactive metals with dilute acids we see that no reaction takes place. For example- when we react to a metallic zinc with the acid that is hydrochloric acid the formation of zinc chloride with the evolution or liberation of hydrogen gas takes place. The chemical equation for that is the following:
$Zn(s)+2HCl(aq)\to ZnC{{l}_{2}}(aq)+{{H}_{2}}(g)$
We see that the metal zinc displaces the hydrogen in the reaction.

Note: The other example for acid reacting with metal is zinc reacting with sulphuric acid. In this reaction the zinc displaces the hydrogen thereby forming zinc sulphate and evolution of hydrogen gas takes place.
$Zn+{{H}_{2}}S{{O}_{4}}\to ZnS{{O}_{4}}+{{H}_{2}}$
As we know that metals contain 2,3 electrons in their valence shell which easily gives their electrons to the combining atom. Whereas the bases are electron donors so when metal and a base react together there is no specific direction for the electrons so no reaction occurs.