Assignment #1 (New Unit: Reactions) Conserving MassLO: Demonstrate understanding of conservation of mass. Balance equations.EQ: If your reactants are 2CH4 + O2, how many C, H, and Os will be on the products side of the equation?

LEVEL ZERO VOICECATALYST (10 minutes, individual work):

1. If ice is melting in a cup, heat is travelling from ____ to _____.2. Draw a temperature vs time graph for something undergoing

deposition.3. Count the atoms on both sides of this equation.____ CH4 + ____ O2 → ____ CO2 + ____ H2O

____ Fe + ____ O2 → ____ Fe3O4

AGENDA 11/19-11/20

1. Lecture

2. Practice Activity

3. Worksheet

HOMEWORK

1. Finish Worksheet

• Chemical Equations: Equations that show reactants and products in a chemical reaction

• Reactant: starting materials (left side of equation)

• Products: the new substance(s) formed (right side)

tin + oxygen gas → tin oxide(reactants) (product)

2 Sn + O2 → 2 SnO(reactants) (product)

Coefficient: how many molecules or atoms (comes before the atom or molecule)

Subscript: the little number in a chemical formula that tells how many atoms of an element are in a molecule

2H2O → 2H2 + O2

• In a chemical reaction, atoms are REARRANGED, not destroyed

• In all chemical reactions, the amount of matter is the same before and after the change takes place• No atoms are lost, no atoms are gained

• Law of Conservation of Mass: the total mass before a chemical reaction is the same as the total mass after the reaction

Conservation of mass

Conservation of mass

Conservation of mass

Balance a Chemical Equation

• When you are writing a chemical equation:1. Make sure the symbols and formulas for the reactants and products are

correct

2. Check to make sure both sides are balanced (same number of each atom appears on each side of the equation – reactants and products)

- compare the number of one atom on both sides of the arrow to make sure it’s the same on both sides

Parentheses in Chemical Equations

• When you count atoms inside a parentheses, the subscript following the parentheses multiplies all the atoms inside.

• Ca (OH)2

• Count the atoms:

1 Ca atoms

2 O atoms

2H atoms

Parentheses in Chemical Equations

• When you count atoms inside a parentheses, the subscript following the parentheses multiplies all the atoms inside.

• Ca (OH)2

• Count the atoms:

1 Ca atoms

2 O atoms

2H atoms

Magnesium Demo

1. (Level 0) Write your observations.

Assignment #5 (NEW UNIT: Reactions) Balancing EquationsLO: Demonstrate understanding of conservation of mass. Balance equations.EQ: If your reactants are 2CH4 + O2, how many C, H, and Os will be on the products side of the equation?

Demonstration

1. (Level 0) Write your observations. 2. Share with a partner. Write down anything they said that you

didn’t have.

AGENDA

1. Lecture

2. Demonstration

3. Worksheet

HOMEWORK

1. Finish Worksheet

Assignment #5 (NEW UNIT: Reactions) Balancing EquationsLO: Demonstrate understanding of conservation of mass. Balance equations.EQ: If your reactants are 2CH4 + O2, how many C, H, and Os will be on the products side of the equation?

Demonstration

1. (Level 0) Write your observations. 2. (Level 2) Share with a partner. Write down anything they said

that you didn’t have.3. The reactants were: Mg and O2

The products were: MgO4. (Level 2) With your table partner, write an equation for the reaction and balance it.

AGENDA

1. Lecture

2. Demonstration

3. Worksheet

HOMEWORK

1. Finish Worksheet

Assignment #5 (NEW UNIT: Reactions) Balancing EquationsLO: Demonstrate understanding of conservation of mass. Balance equations.EQ: If your reactants are 2CH4 + O2, how many C, H, and Os will be on the products side of the equation?

LEVEL ZERO VOICEPROCESSING TASK (10 minutes, individual work):

1. Draw a picture that illustrates the law of conservation of mass. Use lots of colors.

AGENDA

1. Lecture

2. Demo

3. Worksheet

HOMEWORK

1. Finish Worksheet