What are the demerits of the chemical equation?

Chemical equation:

• A chemical reaction takes place when reactants react together to form new products.
• The equation that represents this chemical reaction is known as the chemical equation.

Demerits of the chemical equation:

• The concentrations of reactants and products are unknown.
• The time required for completing a chemical reaction is not known.
• The chemical equation cannot tell whether a catalyst is required in the reaction or not.
• It can not be predicted by looking at the chemical equation whether the reaction is exothermic or endothermic.