Answer: The formation of a gaseous product is indicated by an UPWARD ARROW in a chemical reaction.
Explanation:
A chemical reaction is defined as the process whereby chemical bonds between atoms of
substances known as reactants are either formed or broken leading to the formation of products. New substances are usually formed during a chemical reaction. The following are features of chemical reaction:
--> Evolution of gas
--> Formation of a precipitate
--> Change in color
--> Change in temperature
--> Change in state and
--> Formation of new substances.
Some chemical reactions takes place with the evolution of gas. This can be seen in the reaction of Zinc metal with hydrochloric acid. Hydrogen gas is EVOLVED with the formation of zinc chloride.
UPWARD ARROW in a chemical reaction indicates the evolution of a gas. It appears only on the product side and is written next to the gaseous product.
