Question

Write the complete balanced equation for the following.
A) Sodium reacts with oxygen
B) Aluminum reacts with hydrochloric acid

Answer 1

We have to remember that the reaction between metallic aluminum and hydrochloric acid is what is known as an oxidation-reduction reaction or redox reaction. Both oxidation and reduction take place simultaneously. Oxidation reaction is the addition of oxygen or hydrogen.

Complete answer:
We need to know that sodium is a very reactive metal, it tends to react with oxygen to form sodium oxide but this is an unstable compound and soon reacts with hydrogen to form sodium hydroxide. Sodium is the metal that reacts vigorously with oxygen and water. It is an oxidation reaction in which sodium metal oxidizes into its respective oxide.
$4Na + {O_2} \to 2N{a_2}O$
When sodium was heated and put into a jar full of oxygen it generated a lot of heat energy and light, when the reaction was over sodium oxide $\left( {N{a_2}O} \right)$ was left.
The white powder in the jar was sodium oxide after the reaction between sodium and oxygen.
Aluminum reacts with dilute hydrochloric acid at room temperature. The metal aluminum dissolves in hydrochloric acid, producing aluminum chloride and colorless hydrogen gas. The reaction taking place between aluminum and hydrochloric acid is irreversible. And the final products will not react with each other. In molecular form, the reaction looks as follows:
$2Al + 6HCl \to 2AlC{l_3} + 3{H_2} \uparrow$
Aluminum reacts with dilute hydrochloric acid at room temperature. The metal dissolves in hydrochloric acid, yielding aluminum chloride and colorless hydrogen gas. This reaction is irreversible, as the final products will not react with each other.

Note:
We have to remember that an oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.