CHEMICAL AND PHYSICAL

REACTIONS

PHYSICAL PROPERTIES A characteristic of matter that can be

observed without changing the substance into another substance

Examples: Freezing Boiling Melting Hardness Color Shine flexibility Solubility

CHEMICAL PROPERTIES Characteristics of a substance that describe

its ability to change into a new substance

Examples: Burning Rusting Tarnishing

Changing into a new substance requires another chemical, like O2 changing to CO2

PHYSICAL AND CHEMICAL PROPERTIES ACTIVITY Using the objects provided, list the physical

and chemical properties of each object

Create a table to classify each object based on its properties

Use the equipment & substances available

A: Match B: Crayon C: Metal Ring

D

Reacts with waterDoes not reactFlammableNonflammableHardSoftMelts at room temp

EvaporatesPhysical Properties or Chemical Properties

Metallic, non-metallic, magnetic, heat conductor

PHYSICAL AND CHEMICAL PROPERTIES ACTIVITY 2 Using the substance provided, investigate

and report on its chemical and physical properties

Use your Lab Book, create a table with Physical and Chemical Properties noted

PHYSICAL CHANGES The form or appearance of a substance is

altered, without combining it with another substance

Examples?

Ice to water to steam Ice cream melts Make Kool-aid Cut paper

Reversible!!!

CHEMICAL CHANGES A change in matter that results in one or more

new substances

Chemical in the original substance combines with another chemical to create a new substance

Examples? Burning anything Baking cookies Fireworks

Not reversible!!!

EVIDENCE OF CHEMICAL REACTIONS Color change

Heat given off/absorbed

Change in odor

Gas released

Light given off

CHANGES IN ENERGY Is energy released/taken in during a physical

or chemical change?

Energy can be light, heat, or sound

If heat energy is removed during a reaction, it is an exothermic reaction (feels hot)

If energy is added during a reaction, it is an endothermic reaction (feels cold)

COMMON CHEMICAL REACTIONS Photosynthesis

Co2 + H2O = C6 H12 O6 + O2

Respiration O2+ H2O = Co2 + H2O

Combustion

Rusting

MINI-LAB! Determine whether each reaction is

endothermic or exothermic

Make hypotheses for each of the following: Strike a match Vinegar and antacid

Write 3 observations for each

Write a one sentence conclusion for each

RATES OF CHEMICAL REACTIONS How quickly a chemical reaction can take

place

Controlled by 4 things Surface Area Temperature Concentration Substances

Catalysts Inhibitors

REACTANTS AND PRODUCTS Reactants are combined together to create

products

What are the reactants and products in the following equations? C + 2 O CO2 2 H + O H2O

What do you notice about these equations? There are the same number of atoms on the left as

on the right Coefficients, subscripts

BALANCING EQUATIONS Goal- Have the same number of atoms on

both sides of the equation.

Rules Coefficients multiply You can not change subscripts If there is no subscript after an atom, then you

know there is only 1 atom present

Examples on board Practice worksheet