Chemical Properties

Recall: A physical property is a characteristic of a substance that helps us to identify it (colour, texture, density…) A physical property is a characteristic of a substance that helps us to identify it (colour, texture, density…)

A chemical property describes the behavior of a substance as it becomes a NEW substance. A chemical property describes the behavior of a substance as it becomes a NEW substance.

Some common chemical properties include: Combustibility: describes the ability of a substance to burn Combustibility: describes the ability of a substance to burn Flammable: the substance will burn when exposed to a flame. Flammable: the substance will burn when exposed to a flame. Light Sensitivity: some substances will become new substances when they interact with light. Light Sensitivity: some substances will become new substances when they interact with light.

What property is described by each of the following statements: a) Water boils at 100  C b) Alcohol is flammable b) The density of gold is 19.3 g/cm b) Paper burning Physical Chemical

Give one physical and one chemical property of a marshmallow: Physical: white, soft, yummy Chemical: flammable

Chemical and Physical Changes: In a physical change, the substance remains the same (change of state, dissolving) In a physical change, the substance remains the same (change of state, dissolving) In a chemical change the original substance is changed into one or more different substances. In a chemical change the original substance is changed into one or more different substances.

Chemical Change Clues: 1. A new colour appears

Chemical Change Clues: 2.Heat or light is given off

Chemical Change Clues: 3.Bubbles of gas are formed

Chemical Change Clues: 4.A solid material (precipitate) forms.

5. Change in odour

** These only suggest a new substances has formed, you must consider several clues to determine what type of change has taken place. **

Physical or Chemical Change? 1. Mixing kool-aid and water 2. Cloths catching on fire 3. Water boiling 4. Cooking muffins physical chemical

Chemical Property Lab Question: What will happen to a dull and dark copper penny when it is put into a bowl of vinegar and salt. Hypothesis: If you put a dark and dull penny in a salt and vinegar then _____________ _________________________________

Chemical Property Lab Apparatus: Apparatus:  Penny  ¼ cup white vinegar  1 tsp salt  Spoon  bowl

Chemical Property Lab Method Method 1. Record Physical Properties of penny 2. Mix the vinegar and salt in the bowl 3. Dip the penny in the mixture using a spoon 4. Wait a few minutes and remove the penny 5. Record Obervation- Physical Properties of penny ( after being dipped)

Chemical Property Lab Physical Properties Original State of Penny State of Penny after being dipped

Chemical Property Lab Conclusion: explain if your hypothesis was correct or not Conclusion: explain if your hypothesis was correct or not Application: how does this apply to other areas Application: how does this apply to other areas Hand in: Due Thursday, May 1 Hand in: Due Thursday, May 1