1. Chemical Reactions
Apply the Laws of Conservation of Mass/Energy to balance chemical equations.
Construct chemical formulas for common compounds.

2. Equations Used to demonstrate reactions and predict products
Reactants on the left
Products on the right
NaOH + HCl → NaCl + H2O

3. Law of the Conservation of Mass
Mass is neither created nor destroyed
You end up with the same mass and same amount of atoms
C + O2 → CO2

4. Balancing Equations
Must have the same amount of atoms on the left as on the right
H2 + O2 → H2O Not balanced!
2H2 + O2 → 2H2O Balanced!
__Cu + __O2 → __CuO
__Na + __H2O → __NaOH + __H2
__NaOH + __H2SO4 → Na2SO4 + __H2O

5. Molar Mass Mole--6.022 X 1023 atoms of a substance
Molar mass—mass of one mole of a substance
Unit—g/mol
Find the molar mass on the periodic table
Add the masses of elements to determine mass of compound
22.99g/mol g/mol = g/mol

6. Conversion How many grams in 3 moles of NaCl
How many moles in 90.1g of H2O
How many grams in 1.5 moles of BaSO4
How many moles in 103.6g of Pb

7. Molar Ratio Use the numbers in equations to tell the molar ratio
CH4 + 2O2 → CO2 + 2H2O
1 unit of methane for every 2 units of water
2 units of oxygen for every unit of carbon dioxide
16.05g of CH4 gives g of H2O and 44.01g of CO2
How much water would 2 moles of methane give?

8. Types of Reactions Synthesis Decomposition Single-Displacement
A + B → AB
Decomposition
AB → A + B
Single-Displacement
AB + C → A + BC
Double-Displacement
AB + CD → AC + BD

9. Synthesis & Decomposition
Two or more substances react to form one new substance
A + B → AB
2H2 + O2 → 2H2O
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One substance breaks down to form two or more substances
AB → A + B
2H2O2 → 2H2O + O2
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10. Single-displacement & Double-displacement
One element takes the place of another
AB + C → A + BC
Zn + 2HCl → ZnCl2 + H2
Both elements switch places
AB + CD → AC + BD
AgNO3 + NaCl → AgCl + NaNO3

11. Energy Changes Energy is stored in bonds between atoms
Conservation of energy
Can’t be created or destroyed
Reactions break bonds or create new ones
Breaking bonds produces energy
Creating bonds requires energy
Exothermic—energy is released
Combustion—energy given off as heat and light
Endothermic—energy is absorbed (put in)
2HgO + energy → 2Hg + O2