Chapter 5 Lesson 5 Compounds and Chemical Changes

What are Compounds? A compound is formed by the combination of two or more elements. Compounds have properties different from their elements. Compound (Honey Mustard for your chicken nuggets!!)

Names and Formulas All compounds have chemical names. The chemical name tells scientists which elements come together to make the compound. Why are lemons sour?

Names and Formulas Lemons are sour because they each contain a chemical called citric acid. Citric acid is a weak organic acid found in citrus fruits like grapefruit, oranges, limes and lemons. In its pure form citric acid is a white crystalline solid and is sour to taste like all food acids. It is sold as a food additive for cooking and can be found in most supermarkets. The molecular formula of citric acid is C 6 H 8 O 7

What are chemical changes? A chemical change occurs when a brand new substance is created, and is completely different from the original substance. Rust is a chemical change!

What are chemical changes? The use of baking soda as a cleaning medium was created during the Statue of Liberty Renovation from The statue was scheduled to be re-dedicated on July 4, They needed a cleaning process that would quickly clean the interior of the statue while not damaging the metal structure.

Chemical Equations chemistry/chemicalequations/ chemistry/chemicalequations/ A chemical equation is nothing more than a written expression of a chemical reaction that is to take place or that has already taken place. Just like a Math Equation: The math symbol shows the work in answering the problem. The same thing happens in chemistry!

The Law of Conservation of Mass Law Of Conservation Of Mass states that- An amount of mass can be converted into equivalent amount of Energy or Work. Such as burning of fuel. In Chemistry, it states that in a chemical reaction, the mass being produced and the mass of the reactant are equal. (The saying, “you get out of it, what you put into it!”)

Chemical Change A chemical change refers to what happens to a chemical when an outside force or influence affects it. Some chemicals may breakdown when left in sunlight. Others may change states when heated or chilled. When a molecular bond is broken down and forms a new bond, that is known as a chemical change. RESULT: When a chemical change happens, new things are formed or changed entirely!

Types of Chemical Change Color change: Bleach removes the color from clothing and you end up with a material that has a different color to it. So there is a change. You get a new material that has different properties than the materials that you started with. (The same happens when something RED goes through the wash, and all the whites are now PINK!)

Color change

Types of Chemical Change Tarnish: is a combination of chemicals that have reacted with the metal as a result of being exposed to the air. Compare one side of the pan to the other. Tarnish!

Types of Chemical Change Release of Gas: What happens when you add Mentos to soda? Chemical reaction, and a chemical change as the Mentos dissolves and a gas is released! m/videos/mythbusters- strangest-myths/ m/videos/mythbusters- strangest-myths/

Types of Chemical Change A precipitate is a solid formed from the chemical reaction or two solutions. Soap scum is a white or gray filmy layer that covers the surfaces around our showers, bathtubs, and sinks. Soap scum can be found on shower curtains, bathroom fixtures, bathtubs, shower doors, tiling, and more.

Types of Chemical Change Example of Precipitate. Soap Scum!

Types of Chemical Change Release of energy: Heat: Burning wood is a classic chemical change. When wood burns it becomes ash. When it burns it produces heat. This heat is just a product of wood burning and indicates a chemical change. Light: Glow sticks are very common in showing that light is an indicator of a chemical change. Among other things, light from fireworks and light from lightning bugs is also a product from a chemical change.

Types of Chemical Change