Chemical Properties And Chemical Changes

Matter & It’s Properties Chemical Properties & Chemical Changes

Warm Up Question • The hospital cafeteria is ordering hamburger for the year. If the portion size is 125 grams and there are 225 servings a day, how many kg should be ordered for the year? How many pounds should be ordered for a 10 year period?

Answer to Warm Up Question

Chemical Changes • A.K.A.  Chemical Reactions • A process whereby one or more substances interact in such a way as to be converted into a new one or ones. • Chemical properties of a substance may only be determined from observing a chemical change.

Chemical Changes • The ability of a substance to undergo chemical reactions and to form new substances constitutes its chemical properties. • For any single substance, chemical properties are unique & definitive. • A chemical change (or reaction) results in the formation of new substance or substances with generally a different set or sets of physical AND chemical properties.

Chemical Properties Factors affecting a substances Chemical Properties are ultimately based on their Electron Structure / Reactivity. Find your Brainy Smurf and brainstorm chemical properties.

Chemical Properties Examples of Chemical Properties are: • Electronegativity • Reactivity • Ionization Potential • Flammability • pH • Toxicity • Oxidation state preference

Chemical Change/Reaction • Evidence of a chemical change/reaction: Please find your Radioactiveman and brainstorm signs or evidence of a chemical change/reaction.

Chemical Change/Reaction Evidence of a Chemical Change/Reaction are: • Formation of a gas or precipitate • Evolution or absorption of heat • Emission of light • Color change • Obvious change in physical properties of the original substance • Rusting, rotting, decomposing, fermenting, corroding, growing, decaying, odors emitted, sprouting are all descriptors indicating that a chemical change is taking place.

Chemical Reactions • When one or more substances are changed into new substances. • Reactants- stuff you start with • Products- What you make • NEW PROPERTIES • Often times not easily reversed

Review of Properties 1) Chemical Properties:  characteristics that can not be observed without altering the identity of the substance

2) Physical Properties:  Characteristics that can be observed without altering the identity of the substance

Classify the following as chemical or physical properties Chemical Properties

Physical Properties Density Melting point Flammability Color Reactivity Mass Solubility Hardness Boiling point Temperature Volume Electron structure

Toffee Making! A gooey and sticky introduction to the process of candy making.

Toffee Making Lab