Chemical Reactions What is a Chemical Reaction Chemical

Chemical Reactions

What is a Chemical Reaction? � Chemical Reaction - 2 or more substances undergo a chemical change that results in the formation of a new substance. � Also known as a chemical change. � What are the indicators of a chemical reaction? � Evolution of Gas, Light, and/or Heat � Color Change � Formation of a Precipitate

Types of Chemical Reactions � Endothermic Reaction – A chemical reaction where the energy or heat is absorbed and the external temperature goes down. � Example: � The Baking Bread heat is absorbed in the bread during the chemical reaction, and the oven is cooler because of it. http: //www. youtube. com/watch? v=My. Azj. Sdc 3 Fc&fea ture=related

Types of Chemical Reactions � Exothermic Reaction - A chemical reaction where the energy or heat is released and the external temperature goes up. � Example: Campfire ◦ Heat is being released into the environment and you can feel the temperature go up around the fire. http: //www. youtube. com/watch? v=YIf. V 2 Z-4 M 5 E

Chemical Reactions occur in either Open or Closed Systems • • Open System- A system that allows matter to enter from or escape to the surroundings. Closed System- A system that does not allow for matter to enter from or escape to the surroundings. • Example: A chemical reaction taking place inside of a sealed, plastic bag.

Law of Conservation of Mass � This law states that matter cannot be created nor destroyed. � In a chemical reaction, the matter changes into new substances but the amount does not change.