Step-by-step explanation:
The reaction must be written, completed, and balanced.
HCl => H2 + Cl2
To balance this, it is needed to have the same atoms and the same number of atoms on both sides of the reaction.
On the right, there are 2 hydrogens and 2 chlorines.
On the left, there is one per each.
Therefore, to balance this: add only a two next to HCl
2 HCl => H2 + Cl2
Type of reaction: a decomposition reaction.
Answer:
2 HCl => H2 + Cl2
Reaction Decomposition