do now: 1.describe the physical properties of the sugar before and after the chemical reaction....

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)• A change in color

A chemical equation tells the story of a chemical reaction. Our combustion reaction again…

Reactants products

Physical properties

White crystal To yield

Black crystal/powderGas produced

Chemical equation

C12H22O11 + 12 O2 12 CO2 + 11 H2O

Visual model

+

+

Number of atoms 12 atoms carbon+ 22 atoms hydrogen+ 35

oxygen atoms

12 atoms carbon+ 22 atoms hydrogen+ 35

oxygen atoms

Chemical Reaction Dehydration of sugar…

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Physical properties

White crystal To yield

Black crystal/powder and white gas

Chemical equation

C12H22O11 12 C + 11 H2O (vapor)

Visual model

+

Number of atoms 12 carbons 22 Hydrogen 11 oxygen

12 carbons 22 hydrogens 11 oxygens

H2O

Review: How to make a molecule…

No Subscript, There is only 1 atom of oxygen in the molecule

Subscript

Visual modelFormula

6 H2O

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.

KeyRed-Chlorine

Orange-Sodium

Yellow-OxygenGreen-Hydrogen

Violet- Carbon

H2O

1 molecule of H2O

3 H2O

3 molecules of H2O

Let’s now model another chemical equation with our skittles…

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Chemical equation

C + O2 CO2

Visual model

+

Word equation

To yield

Number of atoms

1 atom carbon react with 1 molecule oxygen 1 molecule CO2

1 carbon 2 oxygen 1 carbon 2 oxygen

Is it a balanced equation? How do we know?

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Chemical equation

C + O2 CO2

Visual model

+

Word equation

Number of atoms

1 atom carbon + 1 molecule oxygen 1 molecule CO2

1 carbon 2 oxygen 1 carbon 2 oxygen

More practice…

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Chemical equation

2C + 2O2 3CO2

Visual model

+

Word equation

To yield

Number of atoms

2 atoms carbon react with 2 molecule oxygen

3 molecules CO2

Is it balanced?

2 carbons 4 oxygen 3 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

FridayMore skittle practice…

How would you create a visual model for the following?

O2

Color Key

Chlorine

Cobalt

Oxygen

Hydrogen

Carbon

How would you create a visual model for the following?

2OColor Key

Chlorine

Cobalt

Oxygen

Hydrogen

Carbon

How would you create a visual model for the following?

O2

Color Key

Chlorine

Cobalt

Oxygen

Hydrogen

Carbon

How would you create a visual model for the following?

2O2

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?

COColor Key

Chlorine

Cobalt

Oxygen

Hydrogen

Carbon

How would you create a visual model for the following?

CO2

Color Key

Chlorine

Cobalt

Oxygen

Hydrogen

Carbon

How would you create a visual model for the following?

2CO2

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 CaCO3?

The model above is best represented by:a. H2O

b. 2OHc. HOOHd. H2O2

The above model shows:a. 10 atomsb. 2 moleculesc. 2CH3Cl

d. All of the above

How many total atoms are in the compound CuSO4?

A

B

C

D

How many elements are in 2H2SO4?

A

B

C

D

A

B

C

D

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?

A

B

C

D