Mixtures Unit 1: Measurement & Matter

2 Categories of Matter  Pure Substances  Mixtures

Pure Substances  Composition is the same throughout and does not vary from sample to sample.  CANNOT be broken down by physical changes  Can be an element or compound.

Mixture  2+ pure substances that are mixed together but NOT joined chemically  Examples: The air we breath, gasoline for cars, the sidewalk on which we walk

A mixture of 2 elements A mixture of two elements, e.g. neon (Ne) and hydrogen (H 2 )

A mixture of 1 element and 1 compound A mixture of one element and one compound, e.g. hydrogen (H 2 ) and ammonia (NH 3 )

A mixture of 2 compounds A mixture of two compounds, e.g. water vapour (H 2 O) and carbon dioxide (CO 2 )

Homogeneous Mixtures  Uniform in composition and appearance  Same proportion of components throughout  Consists 2+ substances in the same phase  Also called solutions

Heterogeneous Mixtures  variable appearance and composition

Let’s classify Kool-Aid

Kool Aid has mass and takes up space

Can be separated by allowing water to evaporate

Same composition throughout

You Decide!  Look at the following examples and with your partner determine if it is a heterogeneous mixture, homogeneous mixture, or a pure substance

Chicken Noodle Soup Heterogeneous

Pure Water Pure substance

Tap Water Homogeneous

Coca-Cola Homogeneous

Oreo McFlurry Heterogeneous

Gold Not a Mixture!!

Coffee Homogeneous

Review: Mixtures  Two or more ________________ or _________________ NOT chemically combined.  No reaction between substances.  Mixtures can be uniform (called ________________________) and are known as solutions.  Mixtures can also be non-uniform (called ________________________).  Mixtures can be separated into their components by ________________ or ________________ means.  The properties of a mixture are similar to the properties of its ________________.

Homework  HW Online Homework (Describing Matter) due TONIGHT 8pm  HW Read p by Mon. 9/22/14  HW Read p by Tues. 9/23/14