GENERAL KNOWLEDGE

Detailed explanation-1: -ii) Production of gas: Gas bubbles appear after a chemical reaction has occurred and the mixture becomes saturated with gas.

Detailed explanation-2: -The formation of a gas is the third sign that a reaction may have occurred. The formation of bubbles when two liquids are mixed usually indicates that a gas has formed. A gas can also be formed when a solid is added to a solution.

Detailed explanation-3: -Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color change, formation of a precipitate, formation of a gas, odor change, temperature change.

Detailed explanation-4: -A chemical reaction that produces a gas as one of the products is called a gas evolution reaction. Typically, the reactants of this type of reaction are an acid and a base.

Detailed explanation-5: -Definition: State Symbol State symbols are italicized letters in parentheses that appear after each species in a chemical equation to indicate the physical state of the species: gas = (g), liquid = (l), solid = (s), and aqueous = (aq).