1. Chemical Properties of Matter - Notes

2. Properties of Matter Physical Chemical Reactivity – will it react with other matter or energy. Flammability – will it burn (combust) combustion is process of burning Size Shape Volume Mass Density State of matter Malleability Luster Streak Hardness Cleavage Fracture Can be seen/measured at any time. Seen only when a reaction is taking place. Unable to observe or measure simply by looking at matter.

3. Reactivity = the process of matter going through a chemical change altering the chemical identity of that matter. Matter may react with – Matter – one type of matter reacts with another type of matter ex: baking soda reacting with vinegar Energy – matter reacts with energy ex: plastic reacts with sunlight causing the plastic to become brittle and faded. Remember…Reactivity can not be observed unless a reaction is happening. The physical property of shape can be directly observed at all times…but whether or not a substance will react with another can only be observed when they are actually reacting with each other.

4. Reactivity = the process of a chemical change. What is a chemical change? Chemical changes = the restructuring ( breaking then reforming) of chemical bonds holding matter together. Reaction Fe + O 2 FeO 2 Zn + 2HCl → ZnCl 2 + H 2

5. Because of chemical bonds being restructured… Two things always happen during a chemical change. The chemical properties (identities) of the original substances (the ones that react with each other) change. A new substance is formed.

6. A chemical change is a reaction that changes the chemical properties of the original substances - and also results in a new substance being formed. In a physical change the substance changed does not change its chemical identity and no new substance is formed…because there is no reaction taking place.

7. A chemical equation shows the reactants and the products of a chemical reaction. The formulas for the reactants are written on the left, followed by an arrow (showing a chemical change took place) and the products are written on the right. Fe + O 2  FeO 2 +O2O2 

8. +O2O2  Iron (Fe) Gray Solid Malleable Magnetic Oxygen (O) Clear Odorless Gas Iron Oxide (FeO 2 ) Red/Orange Solid (powder) Brittle Not magnetic +  New substance formed (products) Properties of reactants changed Is this really a chemical change?

9. The Law of Conservation of Mass states that the total amount of mass going into a change is equal to the total amount of mass at the end of the change…the form of matter may change…but not the total amount of mass. A chemical equation summarizes a reaction. It tells you the substances you start with and the substances you get at the end of the change. The total mass of the reactants must = the total mass of the products.

10. Chemical Change In a chemical change (reaction) A new substance forms. The chemical identity of the reactants (the substances that reacted with each other) are changed. If these things are observed… a chemical change has occurred…they are the proof of a chemical change.

11. Unexpected color change This may show a new substance formed Bubbling/Fizzing Bubbling can indicate a chemical change if gas is being produced. However, bubbling can also indicate a physical change - such as when water begins to boil and then turn into water vapor. Chemical change New substance is a gas Physical change Only a Phase change… No new substance Signs of a chemical reaction/change

12. Signs of a chemical change Unexpected appearance of a solid. A solid that forms from during a chemical reaction is called a precipitate. The production of an odor. The production smoke indicates a chemical reaction may be occurring. Production of noise or light.

13. Signs of a chemical change Because chemical bonds - (energy bonds) – are being restructured in a chemical change…signs of a chemical change also include Unexpected change in temperature…warming or cooling

14. . Glow Sticks- release energy in the form of light. Fireworks release energy in the form of light and heat. Hotpacks release thermal energy

15. Flammability = the ability to burn…the burning process, called combustion, is basically an ongoing chemical change.

16. Chemical Properties Reactivity – process of matter going through a chemical change Flammability – ability to burn Chemical properties can not be seen unless a reaction is taking place.

17. Chemical Change = restructuring of chemical bonds Two things always occur in a chemical reaction – proving that the reaction took place. A new substance forms The chemical properties and identity of the original substance change.

18. Signs (indicators) of a chemical change. Sign are indicators…not guarantees. Unexpected color change. Bubbling/Fizzing that is not associated with a state of matter change. Unexpected appearance of a solid, precipitate. Production of an odor. Unexpected temperature change. Firecracker principle – Production of heat, light, noise, and smoke.

19. Draw an example of a chemical change. List the sign (indicators) and the guarantees (proofs).