Unit 1 Stoichiometry Chemistry 2202 September 2007 Contains information written by CDLI

What is Matter?  Matter is defined as anything that takes up space and has a mass  Chemicals are a simple type of matter  Everything is made up of chemical, so they are always around you

What is Chemistry?  The study of matter, its properties, and the changes it undergoes  There are two branches: 1. Pure Deals with describing known substances and discovering new compounds 2. Applied The search for uses for chemical substances

Why use Chemistry?  New chemicals are discovered or produced every day.  The composition (make up) and properties of each new substance is researched and documented  It may take years to fully understand the properties of one substance

 There is a close link between chemistry, technological innovation and society's needs.  Modern society places demands on science and technology to solve problems.  Many of the technologies and conveniences that you are accustomed to are the result of interaction between chemists and technologists. Can you think of any examples?  Chemists discover new materials and their properties, and technologists use the materials and the properties to meet the needs of society.

Environmental Concerns??? The study of chemistry also has implications for the environment - good and bad. As members of society, you have a role in deciding whether the risks of developing and using new substances are worth the benefit derived from their use.  Example: New fuels, pesticides  Can you think of any more?

Properties of Matter  The characteristics that help you to describe matter  Examples of properties are: Physical state Colour Odour  Examples of chemical properties Reactivity with water Reactivity with acids  See table 1.1 on page 5 for a complete list of properties

States of Matter Adding energy Removing energy

Changes in States of Matter  Melting Change from a solid to a liquid  Freezing (or fusion) Changing from a liquid to a solid  Vapourization Change from a liquid to a gas  Condensation Change from a gas to a liquid  Sublimation Change from a gas to solid AND from a solid to a gas

Classifying Matter  Mixture Physical combination of two or more substances Two type:  Heterogeneous – different components are visible  Homogeneous – mixture looks like one substance  Pure substance Has a definite composition that stays the same in response to physical changes  Element Pure substance that cannot be broken down smaller  Compound Pure substance formed by two or more elements Can be broken down into simpler parts (elements or other compounds)

In-Class Assignment  Read over notes handed out last class  Complete the questions highlighted in the boxes  Questions should be completed in class to avoid homework