Do Now: 1.Describe the physical properties of the sugar before and after the chemical reaction. 2.Explain why there were different physical properties at the beginning of the lab and at the end of the lab.

Yesterday we… investigated how evidence of chemical reactions indicates that new substances with different properties are formed.

Evidence of a chemical reaction: (chemical change) Production of a gas (bubbling, fizzing or foaming) A change in temperature or light (an energy change) Appearance of a precipitate (solid material)precipitate A change in color

A chemical equation tells the story of a chemical reaction. Our combustion reaction again… Reactantsproducts Physical properties White crystal To yield Black crystal/powder Gas produced Chemical equation C 12 H 22 O O 2  12 CO H 2 O Visual model +  + Number of atoms 12 atoms carbon+ 22 atoms hydrogen+ 35 oxygen atoms 

Chemical Reaction Dehydration of sugar… Reactantsproducts Physical properties White crystal To yield Black crystal/powder and white gas Chemical equation C 12 H 22 O 11  12 C + 11 H 2 O (vapor) Visual model  + Number of atoms 12 carbons 22 Hydrogen 11 oxygen  12 carbons 22 hydrogens 11 oxygens

H2OH2O Review: How to make a molecule… No Subscript, There is only 1 atom of oxygen in the molecule Subscript Visual modelFormula

6 H 2 O Review: How to make a molecule… Visual modelFormula Coefficient- How many molecules you have.

Let’s make some visual models with SKITTLES You will be able to… 8.5(D) recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts; 8.5(F) recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass. Key Red-Chlorine Orange-Sodium Yellow-Oxygen Green-Hydrogen Violet- Carbon

H2OH2O 1 molecule of H 2 O

3 H 2 O 3 molecules of H 2 O

Let’s now model another chemical equation with our skittles… Reactantsproducts Chemical equation C + O 2  CO 2 Visual model +  Word equation To yield Number of atoms  1 atom carbon react with 1 molecule oxygen 1 molecule CO 2 1 carbon 2 oxygen

Is it a balanced equation? How do we know? Reactantsproducts Chemical equation C + O 2  CO 2 Visual model +  Word equation  Number of atoms 1 atom carbon + 1 molecule oxygen 1 molecule CO 2 1 carbon 2 oxygen

More practice… Reactantsproducts Chemical equation 2C + 2CO 2  3CO 2 Visual model +  Word equation To yield Number of atoms 2 atoms carbon react with 2 molecule oxygen 3 molecules CO 2 Is it balanced? 2 carbons 4 oxygen3 carbons 6 oxygen

With a partner… Instructions: 1.Create visual models for the rest of the chemical equations. 2.Draw an label the visual models. 3. For each equation complete the following stem: The equation is/is not balanced because… Chlorine Sodium Oxygen Hydrogen Carbon Color Key

Chemistry Practice with Qwizdom Remotes Please wait until your teacher asks you to log in with your student id.

The model above is best represented by: a.H 2 O b.2OH c.HOOH d.H 2 O 2

The above model shows: a.10 atoms b.2 molecules c.2CH 3 Cl d.All of the above

6CO 2 + 6H 2 0+ Sun’s light  C 6 H 12 O 6 +6O 2 The above reaction… a.is photosynthesis b.Is respiration c.Transforms radiant energy into chemical energy d.Both a and c.

Organic Molecules all contain… a.Sulfur b.Carbon c.Oxygen d.nitrogen

All of the following are organic molecules except… a.C 6 H 12 O 6 b.CH 4 c.C 6 H 6 O d.H 2 0