do now: 1.describe the physical properties of the sugar before and after the chemical reaction....
TRANSCRIPT
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…
Reactants products
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…
Reactants products
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?
Reactants products
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…
Reactants products
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
