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 + 2O 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 oxygens

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

Friday More skittle practice… How would you create a visual model for the following? O 2 Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? 2O Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? O 2 Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? 2O 2 Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? C o Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? CO Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? CO 2 Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

How would you create a visual model for the following? 2CO 2 Color Key Chlorine Cobalt Oxygen Hydrogen Carbon

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

Which of the models best represents CaCO 3 ?

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

How many total atoms are in the compound CuSO 4 ?

ABCDABCD

How many elements are in 2H 2 SO 4 ? ABCDABCD

ABCDABCD

How many different elements are involved in the reaction above? Punch in your answer into your remote.

Is the above equation balanced? Why?

Is the above equation balanced? Why?

Is the above equation balanced? Why?

Is the above equation balanced? Why?

Chemical equations tell a story of a chemical change where the elements are rearranged to form new substances. All of the following chemical equations indicate a chemical reaction except…

A student observes some sugar as it is heated and burns. The student concludes that a chemical reaction has occurred. Which of the following observations about the burning sugar provides evidence of a chemical reaction?

ABCDABCD