Question

How acids and bases do react with metals?

Answer 1

Hint: When acids and bases are reacted with metals, we can get products as salts with evolution of hydrogen gas.

Complete step by step answer:
Reaction of acid with metal:
When acid is reacted with a metal, salt formation with evolution of hydrogen gas takes place. Metals, which are more active than acids, undergo single displacement reactions.
In the reactivity of metals with hydrogen, potassium is most reactive metal with hydrogen, whereas platinum is the least reactive metal with acids.
When most reactive metals react with dilute acid, violent reaction takes place, whereas when least reactive metals react with dilute acids, no reaction takes place.
Example:
When metallic zinc is reacted with hydrochloric acid, zinc chloride with the liberation of hydrogen gas takes place. We can write the chemical equation as,
$Zn\left( s \right) + 2HCl\left( {aq} \right)\xrightarrow{{}}ZnC{l_2}\left( {aq} \right) + {H_2}\left( g \right)$
Zinc displaces hydrogen in the above reaction.
Reaction of base with metal:
When base is reacted with salt, hydrogen gas is liberated with one more product. Metals like zinc (or) aluminum react with bases.
Example:
When metallic zinc is reacted with sodium hydroxide in the presence of water, the product formed is sodium zincate along with the evolution of hydrogen gas. We can write the chemical equation as,
$Zn\left( s \right) + 2NaOH\left( {aq} \right) + 2{H_2}O\left( l \right)\xrightarrow{{}}N{a_2}Zn{\left( {OH} \right)_4}\left( {aq} \right) + {H_2}\left( g \right)$
Metals that contain 2, 3 electrons in their valence shell readily give electrons to the combining atom. Bases are electron pair donors. When both metal and the base donate electrons, and there is no specific direction for the electrons, hence no reactions occur.

Note:
We can write some of the examples for reaction of acid with metals as,
In the reaction of sulfuric acid with zinc, zinc displaces hydrogen to form zinc sulfate with evolution of hydrogen gas. We can write the chemical reaction as,
\[{H_2}S{O_4} + Zn\xrightarrow{{}}ZnS{O_4} + {H_2}\]
In reaction between nitric acid and calcium, the calcium displaces hydrogen to form calcium nitrate with evolution of hydrogen gas. We can write chemical reaction as,
$HN{O_3} + Ca\xrightarrow{{}}Ca{\left( {N{O_3}} \right)_2} + {H_2}$
Hydrochloric acid reacts with calcium to form calcium chloride with the liberation of hydrogen gas. In this reaction, calcium displaces hydrogen in hydrochloric acid to form calcium chloride. We can write the chemical reaction as,
\[HCl + Ca\xrightarrow[{}]{}CaC{l_2} + {H_2}\]