EVERYDAY SCIENCE

Detailed explanation-1: -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-2: -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: -A chemical change can be indicated by a change in colour, change in temperature (exothermic or endothermic), change in smell, formation of a precipitate, or the formation of gas bubbles.

Detailed explanation-4: -Release of Gas An example of a chemical reaction that produces a gas is the reaction between baking soda and lemon juice (citric acid). If you mix baking soda with lemon juice (or vinegar), both substances quickly react to form bubbles. The bubbles are made of carbon dioxide gas (CO2(g)).

Detailed explanation-5: -The production of gas does not always mean a chemical reaction has occurred because there is also the evolution of gas when there is a physical change. As we know that we can not create the mass, also we can not destroy it. When a change occurs chemically, a new kind of substance should always be formed.